Metallurgy, Foundry & Forge

The names and compositions of specific elemental metals and mixed metallic materials.

• Alloyant
  An element or material added to a base metal to modify its physical or chemical properties.
• Aluminium bronze
  A family of copper-based alloys containing a significant percentage of aluminium.
• Amalgam
  An alloy formed by combining mercury with another metal.
• Bean shotalso bean-shot copper
  Small pellets of refined copper formed by pouring the molten metal into water.
• Bean-shot copperalso bean shot
  Copper that has been granulated into small pellets by pouring it into cold water.
• Bimetalalso bimetallic strip, thermostatic bimetal
  A composite material made of two different metal layers bonded together.
• BMS
  Bright mild steel, a low-carbon steel that has been cold-finished to a smooth surface.
• Bronzing
  The process of applying a bronze coating or a bronze-like chemical finish to a metal surface.
• Cuprotitanium
  A master alloy of copper and titanium used as an additive in metal production.
• Duplex
  A metallurgical structure consisting of a roughly equal mixture of two distinct phases.
• Duralumin
  A historic trade name for a strong, lightweight aluminium alloy containing copper and magnesium.
• High-entropy alloyalso HEA
  A metallic material made from five or more elements in roughly equal proportions.
• Iron
  A base metal element and the primary constituent of steel and cast iron.
• Manganesic
  Containing or relating to a high proportion of the element manganese.
• Niello
  A black metallic alloy of sulfur, copper, silver, or lead used for surface decoration.
• Refractory metal
  A class of metallic elements highly resistant to heat and wear, typically melting above 2000°C.
• Russia iron
  A historic type of sheet iron finished with a glossy, blue-black oxide coating.
• Sable iron
  A premium, historic grade of Russian sheet iron known for its flawless oxide finish.
• Steel
  A strong and malleable alloy of iron and carbon used extensively in structures and tooling.
• STSalso Special treatment steel
  Special treatment steel, a homogeneous armor plate designed for naval and military applications.
• Superalloyalso high-performance alloy
  A high-performance metal designed to retain exceptional mechanical strength and resist surface degradation at extreme temperatures.
• Superduplexalso Superduplex stainless steel
  A highly alloyed stainless steel with an equal mix of austenite and ferrite for extreme corrosion resistance.
• Tutania
  A historic white metal alloy of copper, antimony, zinc, and tin.
• Zircaloy
  A family of zirconium alloys designed for nuclear reactor environments.

The chemical and physical processes used to separate base metals from raw ores.

• Almond furnace
  A historic refining furnace used to separate valuable metals from slag and cinders.
• Archaeometallurgy
  The scientific study of historic and prehistoric metal extraction, smelting and working.
• Basic processalso Gilchrist-Thomas process, basic Bessemer process
  A steelmaking method using alkaline furnace linings and fluxes to remove phosphorus.
• Bessemer process
  A historic method for mass-producing steel by blowing air through molten pig iron.
• Black copper
  An impure, intermediate form of copper produced during the smelting process.
• Blast furnace
  A massive vertical smelting reactor used to reduce iron ore into liquid pig iron.
• Blow in
  The careful, multi-day process of starting up a cold blast furnace.
• Burdenalso charge
  The solid mix of ore, fuel, and flux loaded into the top of a smelting furnace.
• Cazo process
  A historic method for extracting silver from ores by boiling them in a copper vessel with brine.
• Converter
  A refractory-lined vessel where air or oxygen is blown through molten metal to oxidize impurities.
• Converting furnace
  A historic furnace used to turn wrought iron into steel by heating it with charcoal in sealed chests.
• Deadmelt
  To hold molten steel at a high temperature to allow deoxidation.
• Debismuthization
  The metallurgical process of extracting bismuth impurities from refined lead.
• Departeralso parter
  A historic term for a refiner who separates precious metals from each other or from base metals.
• Desiliconisationalso desiliconization
  The chemical removal of silicon from molten iron before it is converted into steel.
• DRIalso direct reduced iron, sponge iron
  Direct reduced iron, an iron source produced by reducing ore without melting it.
• Forestone
  An adjustable cast-iron block used in historic lead smelting hearths.
• Foxtail
  The final cinders or slag produced during the fining of iron.
• Gad
  An old unit of measure for a bloom of iron, typically around 100 pounds.
• Granulated steel
  Steel produced by quenching molten pig iron in water to form small granules.
• Greillade
  Coarsely crushed iron ore prepared for traditional direct reduction.
• Grundy
  Pig iron that has been granulated or formed into small shot. Shop talk
• Hardhead
  Unmelted residual material or tough metallic compounds left over after smelting. Shop talk
• Hydriding
  A reduction process that uses hydrogen gas at high temperatures to convert metal ores into pure metal.
• Kingpiece
  The final convex cake of congealed metal left at the bottom of a furnace after a melt.
• Knobble
  To refine puddled iron into high-quality wrought iron on a specialized charcoal hearth.
• Lancet
  A heavy iron bar used to pierce the clay plug of a furnace taphole. Shop talk
• Liquate
  To separate a mixture of metals by heating it until the component with the lower melting point runs off.
• Liquation
  The process of separating metals with different melting points by partially melting the mixture.
• Loupalso loop, bloom
  A hot, spongy mass of reduced iron ready to be consolidated by hammering.
• Overpole
  To remove too much oxygen from molten copper during the poling process.
• Pachuca tankalso Brown tank
  A tall, cylindrical vessel used to agitate pulverized ore slurries with compressed air.
• Pernot furnace
  A historic steelmaking furnace featuring a rotating circular hearth.
• Piña
  A cone-shaped mass of silver amalgam prepared for distillation.
• Pig iron
  The crude, high-carbon iron tapped directly from a blast furnace.
• Pistol pipe
  A historic curved iron pipe used to preheat blast furnace air.
• Polealso poling
  The process of removing excess oxygen from molten copper to prevent brittleness.
• Puddle ballalso loup, ball
  A spongy mass of hot wrought iron gathered from a puddling furnace.
• Puddling
  A historic process of converting pig iron into wrought iron by stirring it in a reverberatory furnace.
• Reduce
  To strip oxygen or other non-metallic elements from an ore to yield base metal.
• Reductive
  Describing an environment or chemical process that removes oxygen from a metal ore.
• Regenerative furnacealso Siemens furnace, open-hearth furnace
  A high-temperature furnace that captures its own exhaust heat to preheat incoming combustion air.
• Resmelt
  To process previously smelted metal or slag through a furnace a second time to improve purity.
• Reverberate
  To heat metal by reflecting flames and hot gases down from the furnace roof.
• Roast
  To heat an ore in air without melting it, driving off sulfur and moisture.
• Scaffoldalso scaffolding, bridge
  A solid mass of fused material that forms a blockage inside a blast furnace. Shop talk
• Scoriaalso dross, cinder
  The porous, crusty slag or dross left over after smelting metal from its ore.
• Shot samplealso granulated sample
  A granulated sample of metal created by pouring a small amount of the melt into cold water.
• Slaggability
  The capacity of an ore's impurities to melt and separate from the target metal as slag.
• Slaggable
  Capable of being converted into a fluid waste slag during the smelting process.
• Slaglessness
  The condition of molten metal or an ore being entirely free of non-metallic waste.
• Smelting
  The extractive process of heating an ore with a reducing agent to produce base metal.
• Unsmelted
  Describing raw ore that has not yet been processed to extract its metal.
• Wellalso crucible, hearth
  The lowest section of a furnace where molten metal collects before tapping.
• Work-stone
  A sloping cast iron plate placed at the front of a historic metallurgical hearth.

The tools, molds, and techniques required to pour liquid metal into solid shapes.

• Blowholealso gas porosity
  A smooth-walled cavity in a casting caused by trapped gas.
• Cheek
  The intermediate section of a multi-part casting flask located between the cope and the drag.
• Chill
  A metal insert placed in a sand mold to accelerate the cooling rate of a specific region of a casting.
• Chvorinov's rule
  A mathematical formula used to predict how long a metal casting will take to solidify based on its volume and surface area.
• Cold-shutalso cold shut
  A casting or forging defect where two surfaces meet but fail to fuse completely due to low temperature.
• Core print
  A projection on a casting pattern that creates a seat in the mold to hold a sand core securely.
• Coreboxalso core box
  A mold used to shape and pack sand into a solid core for creating internal cavities in a casting.
• Debind
  To extract organic binding agents from a molded metal powder part before sintering.
• Debinder
  A furnace or chemical bath used to extract organic binders from molded metal powder parts.
• Downspruealso downcomer
  The vertical channel in a mold that carries molten metal down to the runner system. Shop talk
• Facingalso mold wash, facing sand
  A fine powder or wash applied to the inside surface of a sand mold to improve the finish of the final casting.
• Flush cast
  Cast to sit perfectly level with the surrounding surface.
• Gatealso tedge
  The specific channel where molten metal enters the mold cavity.
• Hot metal
  Liquid metal tapped from a furnace and ready for casting or further processing. Shop talk
• Hot tearalso hot crack
  A crack that forms in a casting while the metal is still partially liquid and contracting.
• Hot topalso feeder head
  An insulated or exothermic reservoir placed on top of an ingot mold or casting.
• Ingatealso gate
  The final opening through which molten metal enters the main cavity of a mold.
• Invest
  To surround a consumable pattern with a ceramic or plaster slurry to create a casting mold.
• Ladle
  A refractory-lined vessel used to transport and pour molten metal into molds.
• Lance
  A slender iron rod used to suspend and stabilize a sand core inside a mold cavity.
• Lantern
  A perforated metal barrel used as a structural framework for building large sand cores.
• Loam
  A coarse moulding material made of sand, clay and organic matter used for sweeping large castings.
• Matchalso matchplate, oddside
  A contoured block or plate used to support a pattern and define the parting line of a mould.
• Melt outalso dewax
  To evacuate a sacrificial wax or foam pattern from a mould by applying heat.
• Metallostatic
  Relating to the fluid pressure exerted by a column of liquid metal inside a mould.
• Muller
  A heavy mixing machine that uses heavy wheels to knead and coat foundry sand.
• Parting sand
  A dry, non-cohesive sand dusted onto mold halves to keep them from sticking together.
• Pattern
  A physical replica of the final casting used to shape the mold cavity.
• Pipe
  To form a deep shrinkage cavity in the top center of a solidifying ingot.
• Rap
  To strike a casting pattern lightly to free it from the sand mold. Shop talk
• Shankalso shank ladle, pouring shank
  A long-handled carrying frame used to transport and pour a crucible of molten metal. Shop talk
• Slickeralso slick, smoother
  A small hand tool used by moulders to smooth and repair sand surfaces. Shop talk
• Slush-castalso slush cast
  To create a hollow casting by pouring out the liquid center before it freezes.
• Spray
  A branched runner system that feeds molten metal to multiple small cavities in a mould.
• Spruealso downsprue
  The vertical channel through which molten metal enters a mould.
• Stalkalso core arbor, arbor
  An internal metal reinforcement bar used to support a fragile sand core. Shop talk
• Stop off
  To block a portion of a mold cavity with sand so that part of the pattern does not cast. Shop talk
• Strickle
  A profiled wooden or metal tool used to shape sand or loam surfaces in a mold.
• Sullage
  The layer of impurities, slag, and oxidized metal floating on top of a ladle. Shop talk
• Sweep
  A rotating template mechanism used to form large, symmetrical sand or loam molds.
• Try-offalso tryout
  A physical test fit of a mold to check clearances and wall thicknesses. Shop talk
• Underdraughtalso undercut, back draft
  A reverse taper on a pattern that prevents it from being pulled from the mold.
• Water core
  A hollow metal core used in a mold to circulate cooling water during casting.

The methods of heating and hammering solid metal to change its physical form.

• American forge
  A historic ironmaking hearth used for the direct reduction of iron ore into wrought iron.
• Ball
  To gather and heat a mass of spongy iron in a furnace before squeezing or rolling. Shop talk
• Batter
  To strike metal repeatedly to flatten and spread it outward.
• Brute de forgealso forge finish, as-forged
  A rustic blade or metal finish that leaves the raw hammer marks and forge scale intact. Shop talk
• Crocodile squeezeralso alligator squeezer
  A historic jawed machine used to squeeze liquid slag out of a hot puddle ball and consolidate the iron. Shop talk
• Drop hammer
  A heavy forging machine that shapes hot metal by dropping a massive weight onto a die.
• Forge
  To shape metal using localized compressive forces, usually while hot.
• Forgeability
  The ability of a metal to undergo plastic deformation without cracking.
• Forgeable
  Capable of being shaped by hammering or pressing without breaking.
• Hot stamp
  A permanent mark or impression driven into a metal workpiece while it is still at forging temperature.
• Hot workalso hot-working
  To deform metal plastically above its recrystallization temperature.
• Redsearalso red-short, hot-short
  A historic term for metal cracking or breaking when forged at a red heat.
• Reedy
  Describing wrought iron or steel that shows longitudinal cracks or splits due to poor welding. Shop talk
• Shinglealso nobble
  To hammer and squeeze a hot ball of wrought iron to expel liquid slag and consolidate the metal.
• Strike while the iron is hot
  To forge metal immediately upon removing it from the heat source before it cools and hardens.
• Swage block
  A heavy cast iron block with shaped holes and grooved edges used by blacksmiths to form metal.
• Upsetteralso upset forging machine, header
  A horizontal forging press used to thicken the ends of metal bars.
• Warm workingalso warm forging
  Deforming metal at temperatures above room temperature but below recrystallization.
• Weldless
  A component manufactured from a single piece of metal without joining processes.

The machinery and operations used to flatten, bend, and form thin metallic sheets.

• Alpha rolling
  A hot-rolling process for titanium alloys performed below the beta transus temperature.
• Baralso bar stock
  A solid, straight length of metal with a uniform and simple cross-section.
• Billet
  A solid block or length of metal ready for further processing.
• Blankholderalso binder
  A clamping ring or plate that grips the edges of sheet metal during deep drawing.
• Blanking
  A sheet metal cutting operation that punches out a flat profile from a larger piece of stock.
• Blooming
  The primary rolling process that reduces a massive cast ingot into a smaller rectangular bloom.
• Cobble
  A piece of hot steel that misfeeds or jams in a rolling mill, creating a tangled, dangerous mess. Shop talk
• Cold rollalso Cold rolling
  To pass metal through rollers at ambient temperature to reduce its thickness and increase its strength.
• Compound curve
  A three-dimensional surface that curves in multiple directions, requiring metal to be stretched or shrunk.
• Earing
  The formation of wavy, uneven edges on a sheet metal cup during deep drawing operations.
• Flange
  To bend the edge of a sheet metal part or pipe to form a projecting rim for attachment or stiffening.
• Hot-rollalso Hot rolling
  To pass metal through rollers at a temperature high enough to prevent work hardening.
• K-factor
  A mathematical ratio used to calculate how much sheet metal will stretch when bent.
• Merchant ironalso merchant bar
  Finished wrought iron or steel rolled into standard, commercially saleable profiles.
• Mill bar
  A rough, intermediate bar of iron rolled directly from a bloom or puddle bar.
• Oil-canning
  A visible waviness or buckling in flat areas of thin sheet metal. Shop talk
• Opener
  A mill worker responsible for separating metal sheets that have bonded together during rolling.
• Pickle
  To immerse metal in an acid bath to remove surface impurities.
• Puddle baralso muck bar
  A rough bar of wrought iron rolled directly from a shingled puddle ball.
• Raise
  To form sheet metal into a hollow shape by hammering it over a stake or die.
• Reduction
  The percentage decrease in a material's cross-sectional area or thickness after rolling or drawing.
• Roller machinealso rolling mill
  A mechanical device equipped with heavy cylindrical rolls used to flatten or shape metal.
• Rollerman
  A mill worker who guides hot metal stock into the rolling machinery.
• Single curve
  A sheet metal shape bent along only one axis without stretching or shrinking the material.
• Splitalso edge split, tear
  A deep crack or tear in metal caused by excessive tensile stress during forming.
• Vitriolalso pickle
  To clean metal surfaces by dipping them in a dilute sulfuric acid bath. Shop talk

The scientific study of how internal crystal structures affect a metal's physical properties.

• Bollarding
  A deformation defect where a cylindrical test specimen bulges outward at the ends instead of the middle.
• Cementation
  A solid-state process where a metal absorbs another element into its surface through prolonged heating.
• Cold flowalso room-temperature creep
  The slow, permanent deformation of a solid material under continuous mechanical stress at ambient temperatures.
• Cold shortalso cold-shortness
  Describes a metal that becomes brittle and prone to cracking when worked or stressed at low temperatures.
• Cold workalso Cold working
  To plastically deform a metal at temperatures below its recrystallization point to alter its properties.
• Dendrite
  A branching, tree-like crystal structure that forms as molten metal solidifies.
• Ductile fracture
  A mode of metal failure characterized by extensive plastic deformation before the material finally tears apart.
• Electrofinishalso Electrofinishing
  To treat a metal surface using an electrical current in a chemical bath to alter its properties or appearance.
• Ferric carbidealso cementite, iron carbide
  A hard, brittle compound of iron and carbon that forms the strengthening phase in steel and cast iron.
• Hot-short
  Prone to cracking or breaking when deformed at high working temperatures.
• Intercrystallinealso intergranular
  Occurring along the boundaries between individual grains in a metal structure.
• Intergranularalso intercrystalline
  Located or occurring between the microscopic grains of a metal.
• Kirkendall effect
  The shifting of a boundary between two different metals caused by unequal rates of atomic diffusion.
• Ledeburite
  The eutectic mixture of austenite and cementite that forms in cast iron at high carbon levels.
• Macrosegregation
  Large-scale variations in chemical composition across a metal casting or ingot.
• Metallurgical
  Pertaining to the extraction, refining, alloying and physical properties of metals.
• Microsegregation
  The uneven distribution of alloying elements at the scale of individual crystalline grains.
• Polygonization
  The rearrangement of dislocations into subgrain boundaries during metal recovery.
• Polygonize
  To rearrange internal crystal dislocations into low-angle subgrain boundaries.
• Postuniform
  Describes the phase of plastic deformation occurring after the maximum load is reached.
• Recrystallization
  The formation of a new, strain-free grain structure in a cold-worked metal upon heating.
• Refractionalso refractoriness
  The ability of a material to withstand extremely high temperatures without melting or breaking down.
• Spark testalso spark testing
  A rapid visual method for identifying ferrous alloys based on the sparks they produce. Shop talk
• Thermal analysis
  The measurement of material properties as they change with temperature.
• Vickers hardnessalso HV, Vickers pyramid number
  A measure of a metal's resistance to indentation using a diamond pyramid.
• Work-hardenalso strain-harden, cold-work
  To increase the hardness of a metal by deforming it while it is cold.

The specific job titles and informal shop terms used by workers on the factory floor.

• Anglesmith
  A specialized blacksmith who cuts, bends, and welds structural iron or steel shapes.
• Behinderalso catcher
  A historic rolling mill worker who caught folded metal sheets and passed them back. Shop talk
• Doubler
  A historic rolling mill worker who folded hot metal sheets to be rolled again.
• Foundress
  A historic title for a woman who operates a metal casting facility or pours molten alloys.
• Gunner
  An operator who uses a pneumatic gun to seal a furnace taphole or apply refractory lining. Shop talk
• Metallistalso metalworker
  A traditional or broad term for a worker, artisan, or expert who specializes in metals.
• Moulderalso molder
  A foundry worker who packs sand around patterns to create the molds for casting metal.
• Slagger
  A worker responsible for removing and managing slag from a furnace. Shop talk