Doc #92 — Blacksmithing and Forge Work

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RECOMMENDED ACTIONS

First week

1. Identify and contact all known blacksmiths and farriers in NZ through the NZABA, farrier associations, and the census network (Doc #8). Classify as critical-skills personnel.
2. Issue guidance: do not dispose of any anvils, forge equipment, or scrap tool steel. Anvils in particular are often undervalued and at risk of being overlooked in initial resource allocation.

First month

3. Inventory anvils, forges, and blacksmithing tooling nationally as part of the skills and asset census (Doc #8).
4. Pair each available experienced blacksmith with 2–4 trainees drawn from the welder/fabricator workforce (Priority 2 trainees, Section 7.1). Begin hands-on training immediately.
5. Establish at least one community forge in each rural district using available anvils, scrap steel fire pots, and local fuel (charcoal or coal). Aim for geographic coverage — no farming community should be more than one hour’s travel from a functioning forge.
6. Secure borax stocks — inventory chemical suppliers, household product stocks (borax is sold as a laundry additive), and industrial users. Allocate for forge-welding use.
7. Begin charcoal production (Doc #102) at a scale sufficient to supply forge operations in areas without coal access or gas supply.

First 3 months

8. First cohort of welder-fabricator trainees reaches Level 1–2 competence — producing useful tools, hardware, and repairs.
9. Test NZ coal grades (Waikato sub-bituminous, West Coast bituminous) for forge suitability. Document results and distribute findings to all smiths.
10. Build prototype power hammers (tire hammers or similar) from scrap materials. Test and document construction methods for replication. Note dependencies: requires electric motor (1–2 HP), pillow-block bearings, welding equipment, and fabrication skills (see Section 3.6 for full dependency chain).
11. Begin casting anvils at NZ foundries (Doc #93) to supplement the existing supply. A 100 kg cast iron anvil with a welded tool-steel face plate is adequate for general work.
12. Develop and distribute a NZ-specific blacksmithing reference — scrap steel identification guide (spark test patterns for common NZ scrap types), heat-treatment colours and procedures, standard tool designs adapted to NZ agricultural needs. Print while printing capability exists.

First year

13. Second and third cohorts of smiths trained — expanding the network to cover all regions.
14. Power hammer capability established in major agricultural regions.
15. Production blacksmithing underway — systematic replacement of worn agricultural tools, production of construction hardware, vessel fittings for maritime program (Doc #138).
16. Standard tool designs stabilised — hoe, spade, ploughshare, hammer, and axe patterns adapted to NZ materials and needs, documented for consistency.

Ongoing (Phase 2+)

17. Continue training pipeline — maintain throughput of new smiths entering the trade.
18. Develop advanced capabilities: spring-making, chain production, complex tooling.
19. Integrate with machine shop workflow (Doc #91) — establish forge-to-machine-shop referral pathways for parts requiring both rough forging and precision finishing.
20. Monitor scrap tool-steel consumption — track depletion of high-carbon and alloy scrap; develop carburising protocols as the long-term alternative.
21. Document and preserve forge-welding knowledge — this is the skill most at risk of being lost if borax supplies deplete and practice declines. Film experienced smiths demonstrating the technique while they are available.

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ECONOMIC JUSTIFICATION

10.1 Person-years to establish

Equipping and training a blacksmith to useful competence:

• Forge construction: 1–3 person-days (using scrap materials)
• Anvil and tool acquisition: Depends on availability — if an anvil exists, zero additional labour; if one must be cast and prepared, perhaps 5–10 person-days (foundry time plus machining)
• Training to Level 2 (useful competence): 3–6 months of regular practice, with access to an instructor for at least the first 2–4 weeks

Total to establish one functioning blacksmith: Approximately 0.3–0.5 person-years, including training time. This is an order of magnitude less than establishing a machinist (Doc #91 estimates 1–2 years to competence for an existing tradesperson, longer for a new entrant).

10.2 Output value

A single competent blacksmith, working full-time, can produce:

• 5–15 hand tools per day (hooks, tongs, small implements)
• 2–5 medium tools per day (hoes, hinges, brackets)
• 1–2 heavy items per day (ploughshares, large brackets, anchor components)
• Uncountable repair value — extending the life of existing tools and equipment

Comparison with alternatives:

• Without blacksmithing, broken tools remain broken (or are replaced only if machine-shop time is allocated — which is slower, more expensive in equipment wear, and misuses precision capability).
• Without blacksmithing, new hardware must be scavenged from existing buildings (destructive) or imported (impossible).
• Historical precedent: pre-industrial NZ communities of 200–500 people typically supported a full-time blacksmith. This ratio is a reasonable planning basis for recovery.²

10.3 Breakeven

The investment (0.3–0.5 person-years per smith, plus negligible material cost from scrap) breaks even within the first one to two months of operation, given the value of the tools, hardware, and repairs produced.³ The cost-benefit case for establishing blacksmithing capability is strong across all plausible recovery scenarios. The planning question is not whether but how many, how fast, and where.

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1. WHY BLACKSMITHING MATTERS FOR RECOVERY

1.1 The gap between machine shops and daily needs

Doc #91 establishes that NZ has a network of machine shops capable of producing precision-machined parts. Those shops are essential for maintaining hydro stations, rebuilding pumps, making wire-drawing dies, and other work requiring tight tolerances. But machine shops are relatively few, their equipment is valuable and finite, and the machinists operating them are a scarce resource. Using a machine shop to make a dozen gate hinges or a set of garden hoes is a misallocation — the lathe time and machinist skill are better spent on work that actually requires them.

Blacksmithing fills the gap. The vast majority of metal objects that NZ will need during recovery — hand tools, fasteners, hardware, brackets, hooks, chains, agricultural implements, simple repair parts — can be made by a smith at an anvil, without power tools, without measuring instruments beyond a ruler and a pair of dividers, and without the months of training required for precision machining. A competent blacksmith can produce a usable hoe from a piece of scrap leaf spring in an hour. A machine shop could produce a more dimensionally precise hoe, but the precision is wasted — a hoe works by being sharp, heavy enough, and attached firmly to a handle. Blacksmithing produces functional objects, not precise ones, and most recovery needs call for function over precision.

1.2 Products a blacksmith can make

The range is broad. Historically, the village blacksmith produced nearly every metal object in daily use:⁴

Agricultural tools:

• Hoes, spades, shovels (blade forged from plate or spring steel, fitted to wooden handle)
• Ploughshares and coulters (heavy forging from thick plate or bar)
• Sickles, scythes, brush hooks (edged tools requiring some heat-treatment skill)
• Hay forks, manure forks (tine forging from rod stock)
• Mattocks, picks, adzes
• Fencing staples, fence wire tensioners
• Chain links for animal tethering and general use

Construction hardware:

• Hinges (strap, T-strap, butt)
• Bolts, through-bolts, lag bolts (with hand-cut threads for precision needs, or headed pins for general use)
• Nails (though machine-made wire nails from Doc #105 are more efficient for volume production, hand-forged nails serve when wire stock is unavailable)
• Hooks (wall hooks, ceiling hooks, pot hooks, S-hooks)
• Hasps, latches, door handles
• Brackets, angles, straps
• Anchor bolts, hold-down clips
• Window and shutter hardware
• Fire grates, pokers, tongs for domestic use

Vessel and maritime fittings (Doc #138):

• Chainplate brackets
• Rudder pintles and gudgeons
• Rigging toggles and shackles
• Mooring cleats and bollards
• Anchor components
• Mast bands and boom fittings

Equipment repair:

• Drawing out broken implement handles (drifting and welding new sockets)
• Forge-welding cracked or broken tools
• Reshaping bent or worn agricultural equipment
• Fabricating replacement linkage pins, clevis pins, cotter pins
• Building up worn surfaces by forge-welding additional material
• Straightening bent shafts and bars (within limits — severe bends may require re-forging)

Tooling for other trades:

• Chisels (wood chisels, cold chisels, masonry chisels)
• Punches and drifts
• Tongs for foundry work (Doc #93)
• Hardy tools, swages, and fullers (tooling for other blacksmiths)
• Drawknives, spokeshaves, froes for woodworking
• Marking and scribing tools

1.3 What blacksmithing cannot do

Blacksmithing has real limitations that should not be minimised:

• Precision: Forged parts are accurate to roughly 1–5 mm at best. Anything requiring tighter tolerance — bearing fits, valve seats, threaded fasteners to standard — needs the machine shop (Doc #91). A blacksmith can make a bolt body and head, but cutting an accurate thread on it requires either a threading die (an imported tool) or a lathe.
• Thin sections: Forging is difficult below about 3 mm thickness. Sheet metal work (bending, cutting, forming thin material) is a different skill set using different tools (brakes, shears, rollers), though there is overlap in some shops.
• Complex shapes: Forging produces relatively simple geometries — bars, flats, tapers, scrolls, rings, simple curves. Complex three-dimensional shapes with internal cavities are better produced by casting (Doc #93) or machining (Doc #91).
• Large volume production: A blacksmith working by hand produces items one at a time. For mass production of simple items (nails, bolts, chain links), powered equipment — trip hammers, power hammers, heading machines — dramatically increases output but requires more infrastructure.
• Consistent alloy control: A blacksmith works with whatever steel is available. Scrap steel is of unknown composition. The smith learns to test steel by spark pattern and forging behaviour, but cannot guarantee specific alloy content the way a steelworks can. For critical applications (springs, cutting edges, structural members under high stress), alloy identity matters, and the smith must be cautious about what scrap is used for what purpose.

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2. FORGE CONSTRUCTION

A forge is a controlled fire that heats steel to working temperature — typically 800–1,100°C for mild steel, recognisable as a bright orange to yellow-white colour.⁵ The smith places the workpiece in the fire, heats the section to be worked, removes it, and shapes it on the anvil before it cools below working temperature. This cycle repeats until the piece is finished.

2.1 Types of forge

Coal/coke forge (solid fuel): The traditional forge burns coal or coke in a shallow fire pot, with an air blast supplied from below through a tuyere (a pipe opening in the bottom of the fire pot). The air blast — historically provided by bellows, in modern practice by an electric blower or hand-cranked blower — controls the fire’s intensity. A coal forge can reach welding heat (above 1,300°C for forge welding of mild steel) with a good-quality fuel and adequate air supply.⁶

NZ has domestic coal from the Waikato (sub-bituminous) and West Coast (bituminous). Bituminous coal, particularly lower-volatile grades, is preferred for forge work because it cokes well — it softens, swells, and forms a porous, hot-burning coke that maintains a deep fire bed. Sub-bituminous coal burns but does not coke as well and produces a less concentrated fire.⁷ West Coast bituminous coal is the better forge fuel, but transport from the South Island to North Island smiths requires either rail/ferry or coastal shipping. Waikato sub-bituminous coal is adequate for most forge work if managed properly — the fire requires more attention and the smith must learn to manage a looser fire bed.

Construction: A basic coal forge can be built from locally available materials in a few days:

• Fire pot: a steel plate box approximately 400 mm square and 100–150 mm deep, or a section of large-diameter steel pipe, or a cast iron pot. Scrap brake drums from heavy vehicles work well as impromptu fire pots.⁸
• Tuyere: a steel pipe (25–40 mm diameter) entering the bottom of the fire pot, with an ash dump valve below.
• Air supply: an electric blower (a bathroom exhaust fan or small centrifugal blower provides adequate air for a small forge; a larger industrial blower for production work), or a hand-cranked blower salvaged from agricultural equipment, or traditional bellows (built from wood and leather).
• Table: a steel-topped table surrounding the fire pot, at a comfortable working height (approximately 700–800 mm, depending on the smith’s height). Provides a surface to rest long workpieces while the working end is in the fire.
• Hood and chimney: to carry away smoke. Essential for indoor forges. Sheet steel fabrication — a simple truncated pyramid above the fire, leading to a flue pipe. Outdoor forges can work without a hood.

Charcoal forge: Charcoal (Doc #102) is an excellent forge fuel — it burns cleaner than coal, produces less smoke and sulfur (sulfur in coal can cause “hot short” — brittleness when steel is worked at high temperature), and is available from NZ’s extensive timber resources.⁹ Charcoal forges use the same basic construction as coal forges. The disadvantage of charcoal is consumption rate: charcoal’s mass energy density (approximately 29–30 MJ/kg) is comparable to or slightly higher than many coal grades by weight, but charcoal has a bulk density of only approximately 200–300 kg/m³ versus 800–1,200 kg/m³ for coal. A charcoal forge therefore consumes 3–4 times the volume of fuel per unit of energy compared with coal, requiring more frequent replenishment and larger on-site fuel storage.¹⁰ For NZ, where timber is abundant but coal requires mining and transport, charcoal may be the more practical fuel for rural and small-town smiths, provided adequate charcoal production and storage capacity exists.

Historically, charcoal was the standard forge fuel worldwide before coal became widely available. Maori and early European settlers in NZ used charcoal-fired forges.¹¹

Gas forge: NZ has domestic natural gas from the Taranaki Basin, and LPG (propane) distribution throughout the country. A gas forge uses a burner directing a flame into an insulated chamber (typically lined with ceramic fibre blanket or castable refractory). Gas forges heat quickly, provide even heat, and require less fuel management skill than solid-fuel forges. They are the preferred forge type in modern NZ blacksmithing shops.¹²

Under recovery conditions, gas supply depends on the continued operation of Taranaki gas fields and the LPG distribution network. Natural gas is available in the North Island via pipeline; LPG is distributed nationally in cylinders. Gas supply is finite and subject to depletion of field reserves and cylinder stock, but the timeline is years to decades, not months. A gas forge is viable in the near term; smiths should be prepared to transition to solid fuel (coal or charcoal) as gas becomes less available.

Electric forge (resistance or induction heating): Under baseline grid conditions, electric heating is available. Resistance forges use electric heating elements to heat a chamber; induction forges use electromagnetic fields to heat the workpiece directly. Induction heaters are fast and efficient but require power electronics (imported, finite). Resistance heaters are simpler — nichrome or silicon carbide heating elements in an insulated box — but typically reach only 1,000–1,100°C, adequate for forging mild steel but marginal for forge welding and heat treatment of high-carbon steel.¹³

Electric forges avoid the fuel supply question entirely as long as the grid operates. A small resistance forge drawing 5–10 kW serves a single smith adequately. The grid can support large numbers of electric forges given NZ’s generation capacity. The constraint is the heating elements — nichrome wire and silicon carbide elements are imported — but they have long life (years of daily use) and the initial stock in NZ (from kiln manufacturers, pottery suppliers, and industrial furnace suppliers) would last for a significant period.

2.2 Which forge type for NZ recovery

The answer varies by location and phase:

Situation	Recommended forge type
Urban/industrial area, grid-connected, near term	Electric or gas — simplest, cleanest, no fuel logistics
Rural North Island, gas available	Gas — convenient, effective
Rural South Island, near West Coast coalfields	Coal — local fuel supply
Rural anywhere, timber-rich	Charcoal — fuel can be produced on site
Grid failure contingency	Coal or charcoal — no electricity dependency
Mobile/field forge for on-farm repairs	Charcoal — can be built from scrap, fueled from local timber

Most NZ smiths should plan for at least two fuel options — a primary fuel for normal use and a fallback if the primary becomes unavailable.

2.3 Forge construction cost and timeline

A basic functional forge can be built in 1–3 days from scrap materials by a person with basic fabrication skills (welding, cutting) and access to a grinder, welder, and cutting tools.¹⁴ The fire pot, table, and hood require perhaps 50–100 kg of steel plate and pipe, plus an air supply (electric blower, hand-cranked blower, or fabricated bellows). An anvil, hammers, and tongs are the harder items to acquire (Section 3). Total startup cost in labour and materials is modest by comparison with other manufacturing trades — but the build does require a working welder and cutting equipment, which are themselves dependent on grid power or gas supply. A smith with a complete setup — forge, anvil, tongs, hammers, and fuel stock — can begin producing useful output within a week.

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3. ESSENTIAL TOOLS

3.1 The anvil

The anvil is the blacksmith’s primary workstation — a heavy block of steel (or historically, iron with a steel face plate) on which hot metal is hammered into shape. A good anvil has a flat face (the main working surface), a horn (a tapered cone for bending and curving), a hardy hole (a square hole for mounting bottom tools), and a pritchel hole (a round hole for punching through).¹⁵

Anvil weight matters. A heavier anvil absorbs less energy from hammer blows, transmitting more force into the workpiece. For general blacksmithing, an anvil of 70–150 kg is practical. For heavy work (agricultural implement forging, large stock), 150–250 kg or more is preferable. For light work (hardware, small tools), 30–70 kg is adequate.

NZ anvil supply: NZ has an unknown number of anvils scattered across farms, workshops, heritage collections, and the existing blacksmithing community. Anvils are extremely durable — a 100-year-old anvil in decent condition is fully functional — and NZ’s colonial and agricultural history means that anvils were once commonplace. Many still exist, unused, in sheds and workshops. The national census (Doc #8) should include anvils as a specific inventory item.

Anvil substitutes: If purpose-built anvils are insufficient:

• A section of heavy steel rail (railway rail) mounted vertically in a stump makes a serviceable improvised anvil. The rail head provides a flat striking surface and the profile provides edges and curves for basic forming. NZ has railway lines throughout the country; decommissioned or surplus rail sections are available.¹⁶ The performance gap relative to a purpose-built anvil is significant: a 15–30 kg rail section absorbs substantially more hammer energy than a 100+ kg forged anvil (the rebound coefficient is lower, meaning more energy is lost to heat and vibration rather than transferred into the workpiece). In practice, a smith working on a rail anvil for heavy tasks may need 40–70% more hammer blows to achieve the same deformation, increasing fatigue and reducing throughput. The rail anvil also lacks a hardy hole and pritchel hole, requiring separate tooling jigs for punching and cutting operations. A rail anvil is adequate for light to medium work — hooks, hinges, simple hardware — but is a genuine constraint for heavy agricultural implement forging.
• A thick slab of steel plate (50–100 mm thick, 200 mm or wider) welded to a base provides a flat working surface, though without the horn, hardy hole, or pritchel hole of a proper anvil — limiting the smith to flat work and requiring separate tooling jigs for bending, punching, and cutting operations.
• A heavy steel cylinder (a large hydraulic ram, a section of heavy pipe filled with concrete) provides a curved surface useful for some bending and shaping operations, but is unsuitable for flat forging and lacks the hard face needed for clean finishing work.
• Anvils can be cast and machined: a foundry (Doc #93) can cast an anvil body from iron or steel, and the face can be hardened or capped with a welded-on tool steel plate. This is how anvils were historically manufactured and is within NZ’s capability.¹⁷

3.2 Hammers

Cross-peen hammer (1–2 kg): The general-purpose blacksmithing hammer. The flat face moves metal directly; the cross peen (a wedge-shaped face perpendicular to the handle) spreads metal in one direction. Most forging operations use this hammer.¹⁸

Straight-peen hammer (1–2 kg): The peen is parallel to the handle rather than perpendicular. Used for drawing out metal along the length of a bar.

Sledgehammer (3–5 kg): For heavy forging, swung by a striker (an assistant) while the smith holds and positions the workpiece. Two-person striking is how heavy forging was traditionally accomplished without power hammers. The smith signals the striker with taps of the hand hammer — one tap means strike, two taps means stop, a tap on the anvil face means stop and wait.¹⁹

Ball-peen hammer (0.5–1.5 kg): The ball face is used for riveting, peening, and texturing. Also useful for general shop work.

All of these hammers exist in NZ in large quantities — in hardware stores, workshops, farms, and homes. Hammers are also straightforward to forge from steel bar stock, making them one of the first products a beginning blacksmith can make (a hammer making a hammer — the bootstrap).

3.3 Tongs

Tongs hold hot metal securely while the smith works it. Different workpiece shapes require different tong jaw profiles:²⁰

• Flat-jaw tongs: Hold flat bar stock
• V-bit (bolt) tongs: Hold round and square bar stock
• Box-jaw tongs: Hold wider flat stock and plate
• Pick-up tongs: General-purpose light gripping
• Scrolling tongs: Specialized for holding scrolls and curved work

A smith needs a minimum of 3–4 pairs of tongs for general work; a well-equipped shop might have 20 or more.²¹ Tongs are one of the standard items a smith makes — forging tongs is an intermediate-level skill and a practical training exercise. NZ’s existing stock of blacksmithing tongs is small (held by practising smiths), but engineering tongs (used in welding and fabrication shops) are widespread and some can serve for forge work.

3.4 Hardy tools (bottom tools)

Tools that fit into the anvil’s hardy hole, with the cutting or forming edge facing upward. The workpiece is placed on the tool and struck with the hammer:

• Hardy (hot cut): A chisel edge for cutting hot metal. The most-used hardy tool.
• Fuller: A rounded edge for creating grooves, starting bends, and drawing out metal over a defined area.
• Swage: A shaped cavity (half-round, V-groove, or other profile) for forming the workpiece to a specific cross-section.

Hardy tools can be forged from tool steel or made by welding a tool-steel cutting or forming edge onto a mild-steel shank. A machine shop (Doc #91) can also produce hardy tools efficiently by milling and grinding, which is one of the practical intersections between the two trades.

3.5 Other essential tools

• Vise (leg vise or post vise): A heavy-duty vise mounted to the floor or a stump, designed to withstand hammering. Blacksmith’s leg vises differ from machinist’s vises in construction — the moving jaw is supported by a leg to the floor, providing rigidity for hot work. These are no longer commonly manufactured but exist in NZ in collections and old workshops. A heavy engineer’s bench vise can substitute for lighter work.²²
• Quench tank: A container of water (and/or oil) for cooling workpieces. A steel drum, a cut-down 44-gallon drum, or a steel trough. Size depends on the work — a tank large enough to submerge the largest workpiece being made.
• Wire brush: For cleaning scale from hot metal.
• Punches and drifts: For making holes. A punch starts the hole; a drift enlarges it to final size. Made from tool steel.
• Swage block: A heavy cast iron or steel block with various shaped grooves, hollows, and holes for forming metal. Useful but not essential — many operations can be done on the anvil alone or with hardy tools.
• Mandrels: Cone or cylinder shapes for forming rings, loops, and collars. Can be turned on a lathe (Doc #91) or improvised from pipe and bar stock.

3.6 Power hammers

A power hammer — either a mechanical trip hammer (gravity or spring-actuated, driven by a motor or waterwheel) or an air hammer (using compressed air to drive the ram) — multiplies the smith’s output dramatically. Tasks that take hours of hand hammering can be accomplished in minutes. Power hammers are essential for production blacksmithing and for heavy work (forging ploughshares, large tools, anchor components).²³

NZ has some power hammers in existing workshops. More can potentially be fabricated. A tire hammer (using a vehicle tire as the spring element, a scrap vehicle axle as the hammer head, and an electric motor to drive the linkage) can be built from scrap materials, but the dependency chain is longer than it first appears: construction requires a working electric welder, angle grinder, drill press, an electric motor (typically 1–2 HP, sourced from old appliances or workshop equipment), pillow-block bearings (available from industrial suppliers while stocks last), suitable steel plate and bar for the frame, and fabrication skills — it is a 2–5 week project at design-and-test stage for an experienced fabricator, or 3–5 days once a proven design is being replicated.²⁴ The motor and bearings are the long-term constraint: electric motors are available in NZ in quantity but are not domestically manufactured, and pillow-block bearings will eventually exhaust imported stocks. Designs for shop-built power hammers are well-documented in blacksmithing literature and online resources (while internet access lasts — these should be printed or saved locally). Output of a tire hammer (approximately 50–200 blows per minute at 15–30 kg ram weight) is equivalent to sustained striker work; a power hammer and a single smith can produce roughly 3–5 times the output of unaided hand forging for heavy work.

Historical precedent: NZ’s 19th-century blacksmith shops commonly used water-powered trip hammers where stream water was available.²⁵ This option remains viable in many NZ locations.

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4. STEEL SUPPLY

4.1 Scrap steel

NZ’s most abundant source of forgeable steel is scrap. The country contains millions of tonnes of steel in various forms, much of it suitable for forge work:²⁶

Vehicle leaf springs: Mild to medium carbon steel (typically 5160 or equivalent — approximately 0.55–0.65% carbon), heat-treatable, excellent for making cutting tools, knives, agricultural implement blades, and any application requiring a hardened edge. Leaf springs are available from scrapped vehicles — NZ has approximately 4.4 million registered vehicles, and the scrap vehicle fleet adds substantially to this.²⁷ Leaf springs are one of the most prized scrap materials for blacksmithing worldwide.

Coil springs: Similar alloy to leaf springs. Smaller vehicle coil springs are useful for lighter tools; heavy truck springs for larger items.

Railway rail: High-carbon steel (approximately 0.7–0.8% carbon), hard and durable. Can be forged but requires higher heat and more effort than mild steel. Excellent for anvil faces, hardy tools, and heavy-duty implements. NZ has extensive rail networks; decommissioned rail is periodically available.

Rebar (reinforcing bar): Mild to medium carbon steel, readily forgeable. Available from demolition sites and concrete demolition. Good general-purpose forging stock.

Vehicle axles and shafts: Medium carbon or alloy steel, often already in convenient round bar form. Useful for tool handles, punches, drifts, and any application requiring round stock.

Structural steel (I-beams, channels, plate): Mild steel, easily forged. Heavy sections can be cut into manageable pieces with an oxy-acetylene torch (while gas lasts) or a hacksaw (slow but reliable). Structural steel is the most abundant scrap category in NZ’s built environment.

Chain: Alloy steel, often high-strength. Individual chain links can be forge-welded into other items or the chain can be cut into short lengths for use as stock.

Farm machinery components: A broken piece of farm equipment is a source of forgeable steel. Tines, blades, discs, linkage parts — all are forgeable stock.

4.2 Identifying scrap steel

A blacksmith working with scrap of unknown composition needs to identify the steel to select appropriate working methods and heat treatment. Field tests include:²⁸

Spark test: Grinding the steel on a bench grinder or angle grinder produces a characteristic spark pattern. Mild steel (low carbon) produces long, straight sparks with few forks. Medium carbon steel produces more forking. High carbon steel produces dense, bushy sparks with many fine forks. Alloy steels have modified patterns — chromium produces shorter, darker sparks; nickel produces shorter, brighter sparks. The spark test is imprecise but useful — an experienced smith can distinguish between broad categories (mild, medium carbon, high carbon, stainless) quickly.

Forge behaviour: How the steel behaves under the hammer at forging temperature — how easily it moves, whether it cracks at the edges, whether it has a “gummy” or “crisp” feel — tells the experienced smith about its composition. This is tacit knowledge that develops with practice.

Heat-treat response: Quenching a small test piece and attempting to file it reveals whether the steel hardens. If the file skates off (the quenched sample is hard), the steel has enough carbon for heat treatment. If the file cuts easily, the steel is low-carbon and will not harden significantly by quenching.

Magnet test: Distinguishes ferrous from non-ferrous metals and can help identify stainless steels (most austenitic stainless steels are non-magnetic; ferritic and martensitic stainless steels are magnetic).

4.3 New steel from Glenbrook

NZ Steel at Glenbrook (Doc #89) produces hot-rolled plate and coil in thicknesses from approximately 1.5 mm to 12 mm. For blacksmithing, the most useful products are:

• Hot-rolled plate (6–12 mm): Can be cut into blanks for tool blades, hinges, brackets, and flat implements. Mild steel (approximately 0.15–0.25% carbon) — forgeable but will not harden for cutting edges without carburising (see Section 5.5).
• Hot-rolled coil, slit to strip: Narrow strips of mild steel for making nails, hooks, small hardware.

What Glenbrook does not currently produce but NZ needs for blacksmithing:

• Bar stock (round, square, flat): The standard starting material for most forging. Glenbrook produces flat-rolled products, not long products (Doc #89, Section 7). If Glenbrook develops wire rod capability, some of this rod could serve as small-diameter forging stock. Larger bar stock would require either rolling mill adaptation at Glenbrook, slitting of plate to approximate bar dimensions, or import via trade.
• Tool steel: High-carbon or alloy steels for cutting tools, punches, dies, and springs. Glenbrook produces basic carbon steel; tool-grade steel requires controlled carbon content and possibly alloying elements that are not domestically available. Scrap tool steel (from existing tools, springs, and machinery components) is the realistic near-term supply.

4.4 Steel supply assessment

NZ’s steel supply for blacksmithing is not a constraint in the near or medium term. Scrap steel is abundant. Glenbrook provides new mild steel. The constraint is not the metal itself but the smith’s ability to identify appropriate scrap for each application and to work it competently. Over the very long term (decades), as scrap stocks of high-carbon and alloy steels are consumed and not replaced, NZ’s ability to make heat-treatable tools depends on either Glenbrook developing higher-carbon steel production or on carburising techniques (Section 5.5) to upgrade mild steel.

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5. CORE TECHNIQUES

This section describes the fundamental forging operations. It is not a substitute for hands-on instruction — blacksmithing is a physical skill that must be practised under supervision to learn safely and effectively. The description here is for planners and readers assessing capability, not as a how-to manual.

5.1 Drawing out

Drawing out lengthens a piece of metal by reducing its cross-section. The smith heats the workpiece and hammers it on the anvil, rotating it 90 degrees between blows to maintain a roughly even cross-section. Drawing out is the most fundamental forging operation — it transforms bar stock into tapered points, flat blades, long handles, and transitional sections.²⁹

What it produces: Tapered points (for stakes, punches, chisels), flat blades (for hoes, shovels, scrapers), long thin sections from thick short stock, decorative tapers for ironwork.

Skill level: Basic drawing out on mild steel is a first-day skill. Achieving even tapers, consistent thickness, and smooth surfaces without cold shuts (folds in the metal caused by hammering at too low a temperature) takes weeks to months of practice.

5.2 Upsetting

Upsetting is the reverse of drawing out — it shortens and thickens a piece by hammering on the end. The smith heats one end of a bar and drives it against the anvil or strikes the cold end, compressing the heated section. Upsetting is used to form bolt heads, tool heads, and any section that needs to be thicker than the original stock.³⁰

What it produces: Bolt heads, rivet heads, nail heads, thickened sections for tool sockets, decorative enlargements.

Skill level: Intermediate. Upsetting sounds simple but requires care — the heated section must be short (roughly 2–3 times the stock diameter) or the bar buckles instead of thickening evenly. The smith must also prevent the cold end of the bar from upsetting where it contacts the anvil, which can split or mushroom the stock.

5.3 Bending

Bending changes the direction of a workpiece. The smith heats the section to be bent and either hammers it over the anvil horn, bends it in the vise, or uses a bending fork (a tool clamped in the hardy hole or vise). Tight bends require heating a short section; gentle curves require heating a longer section.³¹

What it produces: Hooks, rings, scrolls, handles, brackets, chain links, hinges, eyes (loops at the end of a bar).

Skill level: Basic bending is a beginner skill. Producing consistent, clean bends without distorting the stock, and making matched pairs (two identical hinges, for example), requires practice.

5.4 Punching and drifting

Punching makes holes in hot metal. The smith places the heated workpiece on the anvil (over the pritchel hole, or on a bolster plate), positions a punch, and strikes it with the hammer to drive it partway through. The workpiece is flipped, the punch is positioned over the bulge on the other side, and driven through — the slug (waste material) falls out through the pritchel hole. A drift (a tapered, smooth tool) is then driven through the hole to bring it to final size and shape.³²

What it produces: Holes for bolt connections, handle sockets (in hammers, axes, hoes — the “eye” of the tool), rivet holes, chain link openings.

Skill level: Intermediate. Punching requires accurate placement, consistent heat, and attention to metal flow. Misplaced or cold punching cracks the workpiece.

5.5 Heat treatment (hardening and tempering)

Heat treatment transforms the mechanical properties of steel — particularly medium and high carbon steels (above approximately 0.3% carbon). The basic sequence is:³³

1. Hardening: Heat the steel to its critical temperature (approximately 760–830°C for most carbon steels — visible as a cherry-red to bright red colour) and quench rapidly in water or oil. This transforms the crystal structure to martensite, which is very hard but brittle.
2. Tempering: Reheat the hardened steel to a controlled lower temperature (150–350°C, indicated by oxide colours on a polished surface — pale straw at 220°C through purple at 280°C to blue at 300°C) and quench again. This reduces brittleness while retaining useful hardness. The tempering temperature determines the balance between hardness and toughness:
   • Straw (220°C): Maximum hardness — for cutting tools, files, scrapers
   • Bronze (260°C): Good hardness with some toughness — for axes, cold chisels
   • Purple (280°C): Moderate hardness, good toughness — for springs, saws
   • Blue (300°C): Low hardness, high toughness — for springs, screwdrivers

The oxide colour method of temperature indication requires no instruments beyond a polished surface on the steel and adequate natural or incandescent light — fluorescent and LED lighting shift apparent colours and are less reliable for this purpose.³⁴ The method is well-established and has been used reliably since antiquity.

Carburising (case hardening): Mild steel (which has too little carbon to harden by quenching) can be given a hard surface layer by heating it in contact with a carbon source. Traditionally, the workpiece is packed in charcoal powder in a sealed steel box and heated to 900–950°C for 4–8 hours. Carbon diffuses into the surface layer to a depth of approximately 0.5–1.5 mm, increasing its carbon content to a level that will harden by quenching. The result is a part with a hard, wear-resistant surface and a tough, ductile core — ideal for items like gear teeth, bearing surfaces, and wearing faces of agricultural implements.³⁵

This is relevant because Glenbrook produces mild steel. If NZ’s scrap supply of high-carbon tool steel is eventually consumed, carburising provides a pathway to make hardenable tools from mild steel, albeit with a hard surface layer only, not through-hardened.

5.6 Forge welding

Forge welding joins two pieces of steel by heating them to welding heat (approximately 1,300–1,400°C for mild steel — a bright yellow-white colour, with surface sparks from burning scale) and hammering them together. At welding heat, the steel surfaces fuse under pressure. Flux (traditionally borax or silica sand) is applied to the joint surfaces before welding to dissolve oxide scale and promote clean metal-to-metal contact.³⁶

What it produces: Joined assemblies — chain links closed by welding, tool heads welded to handles, reinforcing pieces welded onto worn tool edges, composite tools (hard steel edge welded to soft steel body — the traditional construction for axes, plane irons, and edged tools).

Skill level: Advanced. Forge welding is the most demanding basic blacksmithing technique. The temperature window is narrow — too cool and the surfaces do not fuse; too hot and the steel burns (oxidises irreversibly, destroying the material). The joint must be prepared correctly, fluxed, and struck quickly and accurately once at heat. A forge weld that looks good but has an internal oxide inclusion is a weak weld that will fail in service. Reliable forge welding takes months to years of practice.³⁷

NZ context — borax supply: Borax (sodium tetraborate) is the standard forge-welding flux. NZ does not mine borax; it is imported, primarily from Turkey or California.³⁸ Existing NZ stocks (held by chemical suppliers and in household laundry products) are finite. Silica sand (available in NZ) works as a flux for mild steel but is inferior for higher-carbon steels. Forge welding without flux is possible but requires higher skill and produces less reliable joints. Long-term, borax resupply via Australian trade is the most likely pathway — Australia holds larger commercial stocks than NZ due to its industrial base, and borax is a high-value, low-volume trade item well suited to sail trade.³⁹

5.7 Annealing and normalising

Annealing softens steel for easier working — the smith heats the workpiece to above its critical temperature and allows it to cool very slowly (traditionally buried in dry sand, vermiculite, or ashes). This produces the softest possible state, useful for filing, drilling, or further forging of hardened steel.⁴⁰

Normalising refines the grain structure of steel that has been worked at high temperature. The smith heats to slightly above critical temperature and allows the piece to cool in still air. Normalising produces a uniform, fine-grained structure with good mechanical properties — it is the standard finishing treatment for forged parts that do not need to be hardened.⁴¹

Both techniques are important for producing quality work. A forged tool that is neither normalised nor heat-treated has an uncontrolled grain structure and may have poor performance. Normalising costs nothing but time and knowledge.

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6. PRODUCTS IN DETAIL — PRIORITY ITEMS FOR RECOVERY

6.1 Agricultural tools

Agriculture is NZ’s survival base. Tools break, wear out, and need replacement. NZ’s pre-event tool supply is entirely imported — the country does not manufacture hand tools.⁴² When existing tools fail, replacements must be forged.

Hoe (draw hoe): A flat blade approximately 150–200 mm wide, 100–150 mm deep, with a socket or tang for a wooden handle. Forged from a piece of 6–10 mm plate or a section of leaf spring (for a hardenable edge). A competent smith produces one in 30–60 minutes.⁴³

Spade/shovel blade: A larger, shaped blade with a turned edge and socket. More complex than a hoe — requires more material and more forming work. A good smith produces one in 1–2 hours. The socket (where the handle inserts) is the most difficult part — it must be formed from flat stock by bending and welding, or punched and drifted from thicker stock.

Ploughshare: A heavy forging — the cutting point of a plough, which must withstand enormous forces in soil and rock. Traditionally forged from a thick steel slab (25–50 mm), drawn out to the required shape, and hardened. A major forging task, often requiring two-person work (smith and striker) or a power hammer. NZ’s soil types — including heavy clay in the Waikato and stony ground in many regions — impose severe demands on ploughshares.⁴⁴

Fencing staples: Small U-shaped fasteners for attaching wire to wooden posts. Each staple is a short length of rod bent into a U — straightforward as an individual operation but needed in vast quantities: NZ has approximately 50,000–55,000 farms⁴⁵ with fence lines estimated in the hundreds of thousands of kilometres nationally, and each post typically takes 2–4 staples per wire strand. An experienced smith hand-forging staples produces perhaps 300–600 per day; at that rate, supplying a single large farm’s annual staple requirement would occupy a smith for weeks. Power-hammer or heading-machine production is needed for any meaningful volume. In the near term, existing staple stocks (held by farm supply stores — Farmlands, PGG Wrightson) provide a buffer, but depletion timelines depend on normal-rate consumption continuing uninterrupted.

6.2 Construction hardware

Every building repair and new construction project needs metal hardware. NZ’s current hardware supply is entirely imported — NZ does not manufacture hinges, bolts, screws, nails, or general construction fasteners at any significant domestic scale.⁴⁶

Hinges: A strap hinge (the simplest type) is two flat bars, each with an eye at one end, joined by a pin through the eyes. A competent smith produces a pair of functional hinges in 30–60 minutes. Decorative hinges take longer but use the same techniques.⁴⁷

Bolts: A bolt is a round or square bar with a head forged on one end (by upsetting) and a thread on the other. Forging the body and heading is straightforward blacksmithing; cutting the thread requires either a threading die (an existing imported tool — NZ has stocks of dies in hardware stores and workshops) or access to a lathe (Doc #91). For applications that do not require a nut-and-bolt connection, a headed pin with a cotter pin or wedge provides a simpler alternative.

Nails: Hand-forged nails are the iconic blacksmithing product. A nail is a tapered point with a head — forged from nail rod (a thin bar, approximately 5–8 mm square) by pointing, cutting to length, heading in a nail header (a plate with holes), and sometimes quenching for hardness. An experienced smith produces 200–400 nails per day. This is slow compared to machine-made wire nails, but hand-forged nails have superior holding power due to their tapered, rough-textured shank.⁴⁸ For volume nail production, wire-drawing (Doc #105) and nail-making machines are far more efficient; hand-forged nails are the fallback when those systems are not yet available or for specialised applications (large timber framing nails, boat nails).

6.3 Chains

Chain is essential for agriculture (tethering, towing, lifting), maritime use (anchor chain, mooring chain), and general industrial use. Hand-forged chain is made link by link: a short length of round or square bar is bent around a mandrel to form an oval, and the open ends are forge-welded to close the link. Each link is forged through the previous closed link to create the chain.⁴⁹

Chain-making is slow, labour-intensive, and requires reliable forge welding skill. A skilled chain-maker produces approximately 1–2 metres of medium chain (10–12 mm bar stock) per hour. This was historically a specialised trade, and the quality of the forge welds is critical — a failed weld under load can be lethal. Chain made from larger stock (anchor chain, heavy towing chain) requires power-hammer assistance.

For NZ’s recovery, hand-forged chain fills urgent needs but is not a long-term production strategy. Welded chain (made by bending links from rod and electric-welding the joint) is faster and can be produced in any welding shop. Electric welding chain is standard modern practice and does not require forge-welding skill.⁵⁰

6.4 Vessel fittings

NZ’s maritime recovery (Doc #138) requires metal fittings for sailing vessels. Many of these are forging tasks:

• Chainplates: Flat straps that anchor the standing rigging to the hull — forged from flat bar, with holes punched or drilled at each end.
• Pintles and gudgeons: The hinge mechanism for rudders — cylindrical pins (pintles) that fit into sockets (gudgeons). Forging the pins is straightforward; the gudgeons may require machining for a precise fit.
• Shackles and toggles: U-shaped fittings with cross-pins, used throughout the rigging for connections. Simple forgings that are needed in quantity on each vessel.
• Anchor components: An anchor is a heavy forging (or fabrication) — traditionally a smith’s prestige piece. A simple hook anchor can be forged from heavy bar stock; a more efficient design (plow anchor, CQR-type) involves plate bending and welding as well as forging.

6.5 Tool repair

Perhaps the highest-value work for a recovery blacksmith is not making new items but repairing existing ones. A broken spade handle socket, a worn ploughshare, a cracked axe head, a bent crowbar — each of these can be heated, reshaped, rebuilt, or welded in the forge. An hour of forge work extends the life of an existing tool by months or years.

Tool repair requires more judgment than new production — the smith must assess the steel type (by spark test), evaluate whether the failure is repairable (a crack through the eye of an axe head may be fixable by welding; a shattered blade may not be), and decide on the most effective repair method (forge weld, rivet, sleeve, build-up with welding rod). This decision-making is the core of the working blacksmith’s skill.

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7. TRAINING PATHWAY

7.1 Who to train

Priority 1 — Existing blacksmiths and farriers: NZ has a small but active blacksmithing community, centred around the New Zealand Artist Blacksmiths Association (NZABA) and individual practitioners.⁵¹ Farriers (who shoe horses) have forge skills directly applicable to general blacksmithing. These people are immediately productive and should be identified, classified as critical-skills personnel, and given material support (steel, fuel, anvil, workshop space).

Priority 2 — Welders, fabricators, and fitters: These tradespeople already work with steel, understand metal behaviour, and have workshop skills. They lack specific forge experience but learn quickly — a competent welder can produce useful forgings within days of beginning forge training, because the understanding of heat, metal movement, and workshop practice transfers directly.⁵²

Priority 3 — Farm workers and rural generalists: People in rural areas who need tools and hardware and cannot wait for urban smiths to supply them. Basic forge skills — enough to make a simple hook, straighten a bent bar, or re-point a worn stake — can be taught in a short intensive course (2–3 days of supervised hands-on practice).⁵³ Full competence takes much longer, but even limited skills provide meaningful self-sufficiency for straightforward tasks.

Priority 4 — New entrants: Young people and career-changers learning the trade from scratch. These are the long-term workforce and should be apprenticed to experienced smiths.

7.2 Curriculum

Level 1 — Basic forge work (1–2 weeks intensive, or 2–3 months part-time):

• Fire management: building and maintaining a forge fire (coal, charcoal, or gas)
• Safety: burns, eye protection, hammer grip, workshop awareness
• Drawing out: tapers, points, flat sections
• Bending: hooks, eyes, rings, 90-degree bends
• Cutting: hot cutting on the hardy, cold cutting
• Basic tool making: S-hooks, tent stakes, fire pokers, simple wall hooks
• Steel identification: spark test basics

Level 2 — Intermediate (3–6 months of regular practice):

• Upsetting: bolt heads, tool heads
• Punching and drifting: holes for handles, bolt holes
• Scrollwork: decorative and functional scrolls
• Forge welding: simple lap welds, chain-link welding
• Heat treatment: hardening and tempering for edge tools
• Project work: hinges, latches, simple agricultural tools (hoe, digging fork)
• Tong making: forging your own tongs (an important self-sufficiency milestone)

Level 3 — Competent smith (1–2 years of regular practice):

• Complex tool making: axes, adzes, chisels, ploughshares
• Socket and eye forming for tool heads
• Forge welding of tool steel to mild steel (composite tools)
• Power hammer operation (if available)
• Repair work: assessing and repairing broken tools and equipment
• Carburising and case hardening
• Teaching basic skills to beginners (the multiplier)

Level 4 — Master smith (3–5+ years):

• Complex joinery and assembly
• Vessel fittings and hardware to specification
• Spring making and heat treatment of alloy steels
• Power hammer construction and maintenance
• Production planning: efficient workflow for batch production
• Training apprentices to competence

7.3 Realistic training timelines

Blacksmithing is faster to learn to a useful level than machining (Doc #91), because the tolerances are looser and the feedback is more immediate — the smith can see and feel whether the metal is moving correctly. But genuine competence still requires extended practice:

• Making simple hooks and hardware: 1–2 weeks of supervised practice
• Making reliable agricultural tools: 2–3 months
• Competent forge welding: 3–6 months (this is the skill that takes most practice)
• Heat treating tools reliably: 1–3 months (understanding the principles takes days; achieving consistent results takes months)
• Independent general smith (can take on unfamiliar tasks and figure them out): 1–2 years
• Master smith (can make anything in steel, teach others, build tooling): 3–5+ years

These timelines assume regular practice — at least several hours per day. Weekend hobbyists take proportionally longer.

7.4 Training infrastructure

The training infrastructure for blacksmithing is minimal compared to machining:

• A forge (can be built in 1–3 days from scrap, given welding equipment and cutting tools — Section 2)
• An anvil (the hardest item to source; improvised anvils from rail or heavy plate are the fallback — Section 3.1)
• A few hammers and tongs (widely available or forgeable)
• Steel stock for practice (scrap mild steel — abundant)
• Fuel (charcoal from local timber, coal, or gas)
• An experienced smith to teach (the actual constraint)

The bottleneck is not equipment but instructors. NZ’s small blacksmithing community limits how many people can be trained simultaneously by experienced smiths. The training strategy must cascade: train the welders and fabricators first (they learn fastest), then use those newly competent smiths plus the original instructors to train the next cohort. Each trained smith becomes a training resource for the next group.

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8. RELATIONSHIP TO OTHER METALWORKING CAPABILITIES

8.1 Blacksmithing and machine shop work (Doc #91)

The core distinction: blacksmithing works hot metal by hand to approximate dimensions; machining works cold or warm metal with machine tools to precise dimensions. They are complementary:

Blacksmithing handles:

• Parts where precision does not matter (tools, hardware, structural brackets)
• Work that needs to be done quickly from available scrap
• Field repairs where no machine shop is accessible
• Products needed in small quantities (a few hinges, a set of tools)
• Large-deformation shaping (turning bar stock into a ploughshare)

Machine shops handle (Doc #91):

• Parts requiring tight tolerances (bearing fits, valve seats, threaded connections)
• Parts requiring specific surface finishes (seal seats, sliding surfaces)
• Production of identical interchangeable parts
• Work on hardened materials (grinding, precision turning)
• Thread cutting to standard dimensions

Both together: The strongest workflow combines forge and machine shop. A blacksmith rough-forges a part close to final shape (faster and cheaper than cutting from solid), and a machinist finishes the critical dimensions (faster and more accurate than trying to forge to tight tolerance). Example: a replacement shaft for agricultural equipment — the smith forges the basic shape from scrap axle steel (including any upsets for shoulders and tapers for fits), and the machinist turns the bearing journals and threads to specification. This is how metalworking shops historically operated, and it is the most efficient use of both skill sets.⁵⁴

8.2 Blacksmithing and foundry work (Doc #93)

Casting and forging produce parts with different characteristics:

• Cast parts can have complex shapes and internal cavities but tend to be brittle (especially cast iron) and cannot be easily modified after casting.
• Forged parts are limited to simpler shapes but are stronger and tougher — the forging process aligns the grain structure of the steel, producing a part that resists fatigue and impact better than a casting of the same alloy.⁵⁵

For tooling, forged steel is almost always superior to cast iron for items that must withstand impact (hammers, axes, chisels, tongs). Castings are better for items that need complex shapes and can tolerate brittleness (stove parts, grate components, decorative hardware, machine tool beds).

The foundry (Doc #93) also produces the raw castings from which anvils and swage blocks can be made — complementing the blacksmith’s tooling supply.

8.3 Blacksmithing and welding (Doc #94)

Modern arc welding (MIG, TIG, stick) overlaps with traditional forge welding for joining metal. Under recovery conditions, electric welding is available as long as the grid operates and welding consumables (electrodes, wire, gas) last. Forge welding requires no consumables beyond flux (borax) and fuel.

In practice, most recovery smiths will use both. Electric welding is faster and easier for structural joints, tacking assemblies together, and repair work. Forge welding is the fallback when welding consumables are unavailable, and it is the superior method for joining dissimilar steels (e.g., welding a high-carbon edge onto a mild-steel tool body) because the smith can control the heat precisely at the joint.⁵⁶

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9. CRITICAL UNCERTAINTIES

Uncertainty	Impact if Wrong	Resolution Method
Number of practising blacksmiths in NZ	If fewer than assumed, training bottleneck is worse	National census (Doc #8) — include blacksmiths as specific category
Number and location of anvils in NZ	If insufficient, improvised anvils or casting required	Census — include anvils, forges, and forge tools
Quality and quantity of forge-suitable coal in Waikato	If poor coking quality, smiths in the North Island need charcoal or gas	Test NZ coal grades for forge suitability — first 3 months
Borax stocks in NZ	If small, forge-welding capability is limited once stocks deplete	Inventory chemical suppliers; assess trade prospects for borax
Scrap tool-steel availability over decades	If consumed faster than expected, edge-tool production depends on carburising	Track scrap consumption; develop carburising protocols
Power hammer fabrication feasibility from NZ scrap	If difficult, heavy forging remains slow hand work	Build and test prototype tire hammers — first 6 months
Rate at which agricultural tool stock depletes	Determines urgency of blacksmith deployment	Inventory existing tool stocks at farm supply retailers (Doc #1)

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CROSS-REFERENCES

• Doc #1 — National Emergency Stockpile Strategy (tool stock requisition, borax allocation)
• Doc #8 — National Skills and Asset Census (blacksmiths, anvils, forge equipment as specific census categories)
• Doc #56 — Wood Gasification (gasifier construction requires some forged components; wood gas can power forge blowers)
• Doc #74 — Pastoral Farming (agricultural tool demand — the primary driver for blacksmithing output)
• Doc #89 — NZ Steel Glenbrook (steel supply — plate and potentially bar stock for forging)
• Doc #91 — Machine Shop Operations (complementary precision metalworking; machine shops produce hardy tools and mandrels for smiths)
• Doc #93 — Foundry Operations (anvil casting; complementary casting capability; shared tooling)
• Doc #94 — Welding Electrode Fabrication (welding as complementary joining method)
• Doc #102 — Charcoal Production (forge fuel for areas without coal or gas)
• Doc #105 — Wire Drawing (wire production for nails and fencing — higher-volume alternative to hand forging)
• Doc #138 — Sailing Vessel Design (maritime hardware forged by blacksmiths)
• Doc #157 — Trade Training Priorities (blacksmithing as core recovery trade skill)
• Doc #160 — Heritage Skills Preservation and Transmission (forge welding, hand tool making as heritage skills to preserve)

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1. The New Zealand Artist Blacksmiths Association (NZABA) is the primary organisation for blacksmiths in NZ. Membership is modest — likely in the low hundreds — and members are predominantly artist-blacksmiths, hobby smiths, and heritage practitioners rather than production smiths. NZ’s farrier community (horseshoeing) is somewhat larger and represents direct forge skill. Exact numbers for either group are not available from public sources; the census (Doc #8) should establish this. See: NZABA, https://www.nzblacksmiths.org.nz/↩︎

2. Historical blacksmith-to-population ratios: In 19th-century NZ and comparable colonial societies, communities of 200–500 people typically supported at least one blacksmith. Larger towns had multiple smiths, often specialising (farrier, wheelwright-smith, toolsmith). Census data from 19th-century NZ shows blacksmiths as one of the most common trades. See: NZ historical census data (available through Stats NZ historical archives); NZ history references.↩︎

3. Breakeven estimate for blacksmithing investment: Derived from the output values in Section 10.2 (5–15 items per day at modest material cost) against the 0.3–0.5 person-year training cost. At a conservative valuation of replacement tool cost (retail equivalent), a smith working full-time recovers training investment within 4–8 weeks. This is an order-of-magnitude estimate; actual breakeven depends on tool demand in the smith’s location and the value attributed to the specific items produced. No specific source; internal calculation based on Section 10.2 figures.↩︎

4. The role of the village blacksmith in pre-industrial communities is well documented. See: Bealer, A.W., “The Art of Blacksmithing,” Castle Books, 1969 (revised edition 2009); Andrews, J., “Edge of the Anvil: A Resource Book for the Blacksmith,” Skipjack Press, 1977. The village smith was historically one of the most essential tradespeople in any community, producing and repairing nearly all metal goods.↩︎

5. Forging temperature ranges for carbon steel: mild steel (~0.1–0.25% C) forges well at 800–1,100°C (orange to light yellow). Higher-carbon steels require more precise temperature control to avoid cracking. Colour-temperature correspondence: dark cherry red ~700°C, cherry red ~750°C, bright red ~850°C, orange ~950°C, light orange ~1,050°C, yellow ~1,100°C, light yellow ~1,200°C. These are approximate and vary with ambient light — forge work is traditionally done in subdued light so heat colours are clearly visible. Based on standard blacksmithing and metallurgical references.↩︎

6. Forge fire management and coal forge operation are described in standard blacksmithing texts. See: Weygers, A.G., “The Making of Tools,” Van Nostrand Reinhold, 1973; Hrisoulas, J., “The Complete Bladesmith,” Paladin Press, 1987. The air blast rate and fire management determine whether the fire reaches welding heat.↩︎

7. Coal classification and forge suitability: Bituminous coal (particularly medium-volatile bituminous) is preferred for forge work because it softens and cokes — forming a dense, hot fire bed around the workpiece. Sub-bituminous coal (like most Waikato coal) burns well but does not coke, producing a looser fire that requires different management technique. Anthracite burns very hot but does not coke and is difficult to ignite. See: NZ coal classification in MBIE energy statistics; general forge fuel references in blacksmithing literature.↩︎

8. Scrap brake drums as fire pots: A common improvisation in the global blacksmithing community. Heavy vehicle brake drums are cast iron, approximately the right size and shape for a fire pot, and heat-resistant. Widely recommended in introductory blacksmithing resources.↩︎

9. Charcoal as forge fuel: Charcoal was the exclusive forge fuel worldwide before coal became widely available. It produces less sulfur than coal (sulfur in the forge fire transfers to the steel surface, causing “hot shortness” — cracking during forging). Charcoal forges are slightly more difficult to manage (charcoal burns faster and requires more frequent replenishment) but produce excellent welding conditions due to the low sulfur. See: Doc #102 (Charcoal Production); Bealer (note 2).↩︎

10. Charcoal energy density: approximately 29–30 MJ/kg by mass, comparable to or slightly higher than some coal grades. However, charcoal has a bulk density of approximately 200–300 kg/m3 versus 800–1,200 kg/m3 for coal, so it occupies 3–4 times the volume for the same mass. A charcoal forge consumes fuel faster by volume, requiring more frequent tending. Energy density figures from standard fuel reference data.↩︎

11. Early European forges in NZ used charcoal from native timber. Mission stations and early settlements established forges as one of their first industrial operations. Maori adoption of iron tools and subsequent establishment of their own forges is documented in 19th-century NZ histories. See: Belich, J., “Making Peoples: A History of the New Zealanders,” Penguin, 1996.↩︎

12. Gas forge technology: Atmospheric and forced-air gas burners are used in most modern small-scale blacksmithing shops. A typical single-burner propane forge uses 1–2 kg of LPG per hour and reaches forging temperature within minutes. Gas forges provide consistent, controllable heat but cannot easily reach forge-welding temperature without multiple burners or forced-air designs. See: general blacksmithing equipment references; NZ LPG supply from MBIE energy data.↩︎

13. Electric resistance forge temperatures: Standard nichrome (Ni-Cr) heating elements reach approximately 1,100–1,200°C; silicon carbide elements reach approximately 1,400°C. For most mild steel forging (working range 800–1,100°C), nichrome elements are adequate. For forge welding (>1,300°C) or working high-carbon steel at the upper temperature range, silicon carbide or molybdenum disilicide elements are needed. See: furnace element manufacturer specifications; general heat treatment furnace references.↩︎

14. Forge build timeline: Based on standard practice descriptions in blacksmithing and fabrication references, and the parts list described in Section 2.1. A person experienced in welding and steel fabrication can complete a fire pot, table, hood, and tuyere in 1–3 working days from scrap materials. The air supply (blower or bellows) may add additional time if not salvaged ready-made. See: Weygers (note 4); general metal fabrication references.↩︎

15. Anvil anatomy and specification: Standard blacksmithing references describe anvil features — face, horn, step, hardy hole, pritchel hole. Traditional anvils were forged from wrought iron with a tool-steel face welded on; modern anvils are cast steel (often ductile cast iron or cast medium-carbon steel). See: Andrews (note 2); Bealer (note 2).↩︎

16. Railway rail as anvil: Rail steel (typically to AS 1085 / EN 13674 or equivalent standard) is a high-carbon steel (~0.7–0.8% C) with a hardness suitable for anvil use. A 30–50 cm section of heavy rail (NZ uses Cape gauge 1,067 mm track with rail typically in the 40–50 kg/m range; a 50 cm section weighs approximately 20–25 kg) provides a functional striking surface. This improvisation is widely documented in the blacksmithing community. The performance penalty estimate (40–70% more hammer blows for heavy work) is derived from the anvil rebound efficiency literature — a good forged-steel anvil returns 80–90% of hammer energy to the workpiece; a light improvised steel mass returns approximately 50–65% — and from smith accounts in practical references. The specific percentage range is an estimate, not a precisely measured figure; actual penalty depends on the anvil mass and the work being done. See: Andrews (note 2); Bealer (note 2); general anvil efficiency references.↩︎

17. Anvil casting: Historical anvil manufacture involved casting an iron body and forge-welding a steel face plate. Modern cast steel anvils are one-piece castings in medium-carbon steel, heat-treated for face hardness. NZ foundries (Doc #93) could produce cast iron anvil bodies; face hardness would depend on either casting in a harder alloy or welding on a tool-steel face plate. See: postma, H., “Anvils in America,” postma, 1998 (self-published, comprehensive reference on historical anvil manufacture).↩︎

18. Cross-peen hammer: The standard European-pattern blacksmithing hammer, with a flat face and a wedge-shaped peen perpendicular to the handle. Weight typically 1.0–1.5 kg for general work; heavier (up to 2 kg) for production smiths with developed strength. Japanese and Scandinavian traditions use different hammer patterns. The cross-peen is the most common pattern in NZ’s English-derived smithing tradition.↩︎

19. Striker communication: The smith-and-striker system for heavy forging uses a coded system of taps to communicate during the noise of forging. One tap on the work = strike; taps on the anvil face = stop. This system is universal in traditional blacksmithing and is documented in all major references. See: Bealer (note 2).↩︎

20. Tong types and jaw profiles: See Andrews (note 2); Weygers (note 4). Tong design is specific to workpiece shape — poorly fitting tongs are a safety hazard because the workpiece can slip during hammering. Experienced smiths often make custom tongs for specific jobs.↩︎

21. Tong quantity requirements: A working smith needs sufficient tongs to hold the range of stock sizes and shapes in regular use. Industry and educational references suggest 3–4 pairs minimum for general work (covering flat bar, round/square bar, and general pick-up), with more pairs accumulated as the smith’s work diversifies. See: Andrews (note 2); practical blacksmithing curricula.↩︎

22. Blacksmith’s leg vise (post vise): Differs from engineer’s bench vise in having a spring-loaded jaw and a rear leg extending to the floor, absorbing hammering shock through the building structure rather than through the mounting bolts. These vises are no longer commonly manufactured (Peter Wright, Brooks, and other historical makers ceased production decades ago) but are found in antique and second-hand tool markets. NZ’s colonial-era workshops contained many; some survive.↩︎

23. Power hammers in blacksmithing: Trip hammers (gravity drop, lifted by a rotating cam) have been used since at least the 12th century. Spring hammers (helve hammers with a spring return) were common in European smithies. Modern power hammers include air hammers (Nazel, Chambersburg), mechanical hammers (Little Giant), and hydraulic presses. See: general metalworking history references; Rolt, L.T.C., “Tools for the Job,” HMSO, 1986.↩︎

24. Tire hammer design: A self-built power hammer using a vehicle tire as the spring/linkage element, with a heavy striking head (typically 10–30 kg), driven by an electric motor through a crank mechanism. Designs have been widely shared in the blacksmithing community, with the “Clay Spencer tire hammer” design being among the best-documented. Construction requires basic fabrication skills and scrap materials. See: Clay Spencer, tire hammer plans (documented in Hammer’s Blow, the Artist-Blacksmith’s Association of North America journal, and various online sources — these should be printed for NZ reference before internet access is lost).↩︎

25. Water-powered smithies in NZ: Early European settlements in NZ used water power for various workshop operations, including trip hammers. This follows the English and European tradition of water-powered smithies. NZ’s abundant streams and rivers make this a viable option in many locations. See: general NZ industrial history references; Wilson, J., “Canterbury: A Regional History,” Canterbury University Press.↩︎

26. NZ scrap steel availability: NZ’s total steel-in-use stock is estimated at tens of millions of tonnes across buildings, infrastructure, vehicles, and equipment. Scrap steel is available from demolition, vehicle wrecking, and farm cleanup. The composition varies widely but most structural and automotive scrap is mild to medium carbon steel suitable for forging. See: HERA (Heavy Engineering Research Association) NZ steel industry data; general scrap industry sources.↩︎

27. NZ vehicle fleet: Approximately 4.4 million registered vehicles as of 2023 (Ministry of Transport motor vehicle registration statistics). Each vehicle contains forgeable steel components — leaf springs, coil springs, axles, drive shafts, steering components. See: Ministry of Transport, “NZ Vehicle Fleet Statistics,” https://www.transport.govt.nz/↩︎

28. Spark testing for steel identification: A practical field test used by machinists and blacksmiths since the development of high-speed grinding. The characteristic spark stream varies with carbon content and alloying elements. See: Machinery’s Handbook (Oberg et al., Industrial Press); Weygers (note 4). The test requires practice to interpret reliably but provides useful broad classification.↩︎

29. Drawing out: The most fundamental forging operation, covered in all blacksmithing texts. See: Andrews (note 2); Weygers (note 4); Aspery, M., “The Skills of a Blacksmith,” available through the British Artist Blacksmiths Association (BABA).↩︎

30. Upsetting: See references in note 25. The 2–3 diameter rule (the unsupported length that can be upset without buckling should not exceed 2–3 times the stock diameter) is standard practice, well-established in forging literature.↩︎

31. Bending: See references in note 25. Key considerations include spring-back (metal partially returns toward its original shape after bending — the smith must over-bend slightly to compensate) and distortion of cross-section at the bend (round stock becomes oval at tight bends; square stock distorts).↩︎

32. Punching and drifting: A standard intermediate technique described in all blacksmithing references. The critical principle is to punch from both sides (rather than driving the punch all the way through from one side), which maintains the integrity of the metal around the hole. See: Andrews (note 2).↩︎

33. Heat treatment of carbon steel: The fundamental sequence of austenitising, quenching, and tempering is covered in standard metallurgical texts. See: Verhoeven, J.D., “Steel Metallurgy for the Non-Metallurgist,” ASM International, 2007; Hrisoulas (note 4); any introductory materials science text. Critical temperatures for plain carbon steels are well-established: approximately 727°C (the eutectoid temperature) to ~830°C depending on carbon content.↩︎

34. Oxide colour tempering: The colour-temperature relationship results from thin-film interference in the iron oxide layer that forms on a polished steel surface as it is heated. The colours are: pale straw (~220°C), straw (~230°C), dark straw (~240°C), bronze (~260°C), peacock blue (~280°C), purple (~290°C), blue (~300°C), light blue (~340°C). This method has been used since antiquity and requires no instruments. Colours are most accurately read in natural daylight or under incandescent light; fluorescent and LED light can shift the apparent colour. See: Verhoeven (note 29).↩︎

35. Carburising (case hardening): Pack carburising using charcoal or bone charcoal is the oldest hardening method for low-carbon iron and steel, dating to antiquity. Modern commercial carburising uses controlled gas atmospheres, but pack carburising in sealed steel boxes with charcoal granules is effective and requires no specialised equipment. Carburising depth depends on temperature and time — typically 0.5–1.5 mm after 4–8 hours at 900°C. See: any heat treatment reference; Verhoeven (note 29).↩︎

36. Forge welding: The technique requires bringing both surfaces to welding temperature simultaneously, applying flux (borax or silica sand) to dissolve oxide scale, and striking quickly to forge the joint before the surfaces cool below welding temperature. The critical difficulty is contamination — any oxide or scale trapped in the joint creates a weak inclusion. See: Andrews (note 2); Bealer (note 2). Forge welding is the joining method that predates all others (brazing, soldering, and electric welding all came later).↩︎

37. Forge welding skill development: Industry and educational consensus is that reliable forge welding requires extensive practice. The American Bladesmith Society requires applicants for Journeyman Smith rating to demonstrate a forge-welded billet — and this is considered an intermediate-to-advanced skill milestone. See: ABS testing requirements; general blacksmithing educational literature.↩︎

38. NZ borax supply: Borax is not produced in NZ. Global borax production is dominated by Turkey (Eti Maden) and the USA (Rio Tinto’s Boron mine in California). NZ imports borax for industrial and consumer uses (laundry products, glass manufacturing, ceramic glazes). Total NZ stock at any time is uncertain but probably modest — in the tens to hundreds of tonnes across all distributors and users. See: NZ Customs import data; general minerals supply references.↩︎

39. Australian borax: Australia does not produce borax in large quantities but has identified deposits. More practically, Australia imports and stockholds borax in larger quantities than NZ due to its larger industrial base. Borax is a high-value, low-volume trade item — exactly the kind of goods suited to sail-based trade. See: Geoscience Australia mineral commodity summaries.↩︎

40. Annealing and normalising: Standard heat-treatment operations described in all metallurgical and blacksmithing references. Annealing (slow cooling in insulating material) produces maximum softness; normalising (air cooling) produces a refined grain structure with moderate hardness and good toughness. See: Verhoeven (note 29).↩︎

41. Annealing and normalising: Standard heat-treatment operations described in all metallurgical and blacksmithing references. Annealing (slow cooling in insulating material) produces maximum softness; normalising (air cooling) produces a refined grain structure with moderate hardness and good toughness. See: Verhoeven (note 29).↩︎

42. NZ hand tool manufacturing: NZ does not manufacture agricultural hand tools at any significant scale. Tools are imported primarily from China, Taiwan, and Australia. NZ’s garden and agricultural tool supply is held by retailers (Mitre 10, Bunnings, Farmlands, PGG Wrightson) and distributors. Total stocks are uncertain but probably represent months to a few years of normal-rate consumption.↩︎

43. Hoe forging time estimate: Based on general blacksmithing practice for a simple draw hoe from flat stock. Actual time varies with smith experience, steel type, and forge efficiency. An experienced smith working with good heat and prepared stock can produce a basic hoe in 20–30 minutes; a less experienced smith or one working with difficult stock may take an hour or more.↩︎

44. Ploughshare forging: Historically a major task for the village blacksmith, requiring heavy stock, significant energy, and often two-person work. NZ’s stony and clay soils impose particular demands on ploughshare hardness and toughness. See: Bealer (note 2); general agricultural implement history.↩︎

45. NZ farm statistics: Stats NZ Agricultural Census reports approximately 52,000–55,000 farms depending on the census year and farm definition threshold. Total fence line length in NZ is estimated at several hundred thousand kilometres when pastoral farm fencing is aggregated; total fence posts in the tens of millions. Fencing staple demand is correspondingly large and cannot realistically be met by hand forging alone. See: Stats NZ Agricultural Production Statistics, https://www.stats.govt.nz/; Beef + Lamb NZ farm survey data; DairyNZ industry statistics.↩︎

46. NZ construction hardware manufacturing: NZ does not produce hinges, bolts, screws, nails, or standard construction fasteners domestically at meaningful scale. These products are imported primarily from China, with some sourcing from Australia and Taiwan. Total NZ stock at any given time is held by hardware retailers (Mitre 10, Bunnings, Placemakers), specialist fastener suppliers, and building merchants. Figure requires verification from Stats NZ trade data or MBIE manufacturing statistics; no public figure for NZ hardware import volumes was identified. See: Stats NZ international trade data, https://www.stats.govt.nz/↩︎

47. Hinge forging: A standard intermediate blacksmithing exercise. The eye (the barrel of the hinge through which the pin passes) is formed by drawing out one end of a flat bar to a thin section, then curling it around a mandrel. See: Andrews (note 2); any project-based blacksmithing reference.↩︎

48. Hand-forged nails: Historically, nail-making was a specialised trade (nailer). Production rates of 200–400 nails per day for a skilled nailer are documented in historical records. Hand-forged nails have a tapered, slightly rough-textured shank that grips wood more effectively than smooth wire nails. The nail header (a thick plate with holes of various sizes through which the nail shank is inserted before the head is formed) is an essential specialised tool. See: Loveday, M., “Nail Making,” Shire Publications; Bealer (note 2).↩︎

49. Chain making: Described in Andrews (note 2) and historical metalworking references. Each link must be individually forged, passed through the previous link, and forge-welded closed — a labour-intensive process requiring consistent welding skill. Chain quality depends entirely on the reliability of the forge welds.↩︎

50. Welded chain production: Modern short-link chain is manufactured by forming links from wire or rod and electric-welding (flash welding or resistance welding) the joint. This can be done on a smaller scale with manual arc welding, though the resulting chain should be proof-tested before use in load-bearing applications. Electric-welded chain production does not require forge-welding skill.↩︎

51. The New Zealand Artist Blacksmiths Association (NZABA) is the primary organisation for blacksmiths in NZ. Membership is modest — likely in the low hundreds — and members are predominantly artist-blacksmiths, hobby smiths, and heritage practitioners rather than production smiths. NZ’s farrier community (horseshoeing) is somewhat larger and represents direct forge skill. Exact numbers for either group are not available from public sources; the census (Doc #8) should establish this. See: NZABA, https://www.nzblacksmiths.org.nz/↩︎

52. Welder-to-blacksmith training transfer: Anecdotally well-established in the blacksmithing community — welders and fabricators consistently learn forge skills faster than people without metalworking backgrounds. The shared understanding of heat, metal behaviour, safety practice, and workshop environment provides a strong foundation.↩︎

53. Basic blacksmithing course duration: A 2–3 day intensive introduction, focused on fire management and one or two simple forging operations (drawing a point, bending a hook), is consistent with introductory forge courses offered by the NZABA and similar organisations internationally. This duration is sufficient to produce competent simple hardware under supervision; independent reliable production of even basic items typically requires additional weeks of practice. See: NZABA introductory course descriptions, https://www.nzblacksmiths.org.nz/; ABANA (Artist-Blacksmith’s Association of North America) introductory curriculum guidelines.↩︎

54. Historical forge-to-machine-shop workflow: Before the modern separation of trades, blacksmithing (hot forging to rough shape) and machining (cold finishing to final dimension) were commonly performed in sequence. This approach minimises both material waste (forging is more efficient than machining from solid for large shape changes) and machining time (the machinist finishes only the critical surfaces). See: general metalworking history and practice references.↩︎

55. Forged vs. cast properties: Forging aligns the grain structure (dendritic solidification structure) of steel, improving fatigue resistance, impact toughness, and ductility. Castings retain a dendritic or equiaxed grain structure that is inherently weaker under dynamic loading. For impact tools (hammers, axes, chisels), forged steel is strongly preferred. See: any materials science or manufacturing processes text; ASM Handbook, Vol. 14, “Forging and Forming.”↩︎

56. Forge welding vs. electric welding for dissimilar steels: Forge welding allows the smith to control heat input precisely at the joint, which is advantageous when joining steels of different carbon content (e.g., a high-carbon edge welded onto a low-carbon body). Electric welding of dissimilar steels can create hard, brittle zones at the fusion line due to carbon migration. Forge welding, done correctly, produces a more gradual transition. See: welding metallurgy references; Hrisoulas (note 4).↩︎