Metal Smelting and Casting, Foundries Industry Terminology

Alloy

A metallic material made by combining two or more elements (at least one metal) to achieve desired mechanical, physical, or chemical properties.

Switch to 356 aluminum alloy for better fluidity in thin ribs; Specify ASTM A536 Grade 65-45-12 ductile iron for impact resistance; Use low-alloy steel with molybdenum to improve hardenability.

Annealing

A heat treatment involving heating to a specified temperature and cooling slowly to reduce hardness, relieve internal stresses, and improve ductility and machinability.

Perform full anneal to soften the casting before machining; Add a stress-relief anneal after welding the repair; Anneal malleable iron to convert cementite to ferrite and graphite.

AOD (Argon Oxygen Decarburization)

A secondary steel refining process for stainless and specialty steels that uses oxygen and inert gas to reduce carbon and control impurities while retaining alloying elements.

Route stainless heats to AOD to achieve low carbon without excessive chromium loss; Adjust AOD gas ratios to control sulfur; Plan AOD vessel relining during outage.

APQP (Advanced Product Quality Planning)

A structured, cross-functional methodology used to develop products and processes that meet customer requirements, commonly required by automotive OEMs.

Complete APQP Gate 3 deliverables before tooling kickoff; Align APQP timing with customer SOP date; Track APQP risk actions in the control plan.

Basic Oxygen Furnace (BOF)

A primary steelmaking vessel where high-purity oxygen is blown into molten iron to reduce carbon and refine composition.

BOF tap-to-tap time improved by 5 minutes; Increase oxygen lance rate to boost BOF productivity; Schedule BOF converter relining next quarter.

Blast Furnace

A shaft furnace that reduces iron ore to molten iron (hot metal) using coke and fluxes at high temperatures with preheated air.

Optimize blast furnace burden mix of ore, sinter, and coke; Raise hot blast temperature to save coke; Monitor slag basicity to control silicon pickup.

Brinell Hardness (HBW)

An indentation hardness value obtained by pressing a hard ball into the surface under load and measuring the indentation diameter.

Target 170–220 HBW for machinability; Record HBW on each heat as part of PPAP; Correlate HBW with tensile strength for the alloy family.

Carbon Equivalent (CE)

A calculated value expressing combined effects of carbon and other elements on solidification, hardness, weldability, and shrinkage (formulas differ for iron and steel).

CE of 4.3 indicates near-eutectic iron; Adjust carbon and silicon to hit CE target; Use CE to estimate shrinkage tendency and fluidity.

Casting Yield

The ratio of net casting weight to total poured weight (including gating and risers), indicating process efficiency and metal utilization.

Improve yield from 60% to 75% by redesigning risers; Simulate gating to boost yield while maintaining quality; Track yield loss by pattern for cost reduction.

Cope and Drag

The top (cope) and bottom (drag) halves of a sand mold that come together at the parting line to form the cavity.

Correct cope/drag mismatch causing parting line shift; Spray extra wash on the drag face to prevent burn-on; Balance cope weight to avoid float during pour.

Cupola Furnace

A vertical shaft furnace used primarily for melting cast iron with coke, fluxes, and air blast in a continuous operation.

Extend cupola campaign length by improving refractory; Optimize coke-to-iron ratio; Monitor cupola slag chemistry for sulfur control.

Degassing

The removal of dissolved gases (commonly hydrogen in aluminum) from molten metal to reduce porosity and improve cleanliness.

Use rotary degassing with argon in aluminum to lower hydrogen; Verify hydrogen level with reduced pressure test; Add flux tablets to aid degassing efficiency.

Die Casting

A high-rate casting process that forces molten metal into hardened steel dies under high pressure, typically for aluminum, zinc, or magnesium.

Switch to vacuum die casting to reduce gas porosity; Optimize die thermal balance to cut cycle time; Address soldering in HPDC by changing die lube.

Ductile Iron (SG Iron)

Cast iron in which graphite forms as spheroids (nodules), resulting in higher strength and ductility compared to gray iron.

Specify Grade 80-55-06 for strength and ductility; Maintain nodularity above 85%; Adjust Mg treatment to recover after long holding time.

EAF (Electric Arc Furnace)

A steelmaking furnace that melts scrap, DRI, or HBI using electric arcs between electrodes and the metal.

Improve EAF tap-to-tap time; Increase charge mix of HBI to control residuals; Monitor EAF energy consumption per ton melted.

EBITDA

Earnings before interest, taxes, depreciation, and amortization; a key measure of operating profitability.

Raise pricing to offset energy cost inflation and protect EBITDA; Track EBITDA margin by product family; Bridge EBITDA improvements from yield and scrap reduction.

EHS (Environment, Health, and Safety)

Programs and compliance activities that ensure environmental stewardship, worker safety, and health standards in operations.

Conduct EHS audit of fume extraction and noise; Track LTIR as a core EHS KPI; Implement silica exposure controls in coremaking.

Fettling

Post-casting finishing operations such as removing gates/risers, flash, and surface cleaning to achieve final geometry and surface finish.

Automate the fettling cell with robots; Reduce fettling grind time by improving riser placement; Control dust and noise exposure in fettling.

Flux

A substance added to molten metal to promote impurity removal, protect from oxidation, or adjust slag chemistry.

Add cover flux to limit oxidation in the furnace; Use cleaning flux to remove inclusions from aluminum; Set flux addition rate per ton poured.

FMEA (Failure Modes and Effects Analysis)

A systematic method to identify potential failure modes, assess risk, and prioritize preventive actions for products and processes.

Build a process FMEA for the molding line; Update FMEA occurrence rating after installing a filter; Link FMEA controls to the control plan and SPC charts.

Gating Ratio

The proportional cross-sectional areas of sprue, runner, and gates in a gating system, influencing flow velocity, turbulence, and yield.

Apply 1:2:2 sprue:runner:gate ratio; Shift to pressurized gating to reduce dross; Tune gating ratio based on alloy and section thickness.

Gating System

The network of channels (sprue, runners, gates) that directs molten metal from the pouring basin into the mold cavity.

Redesign runners and gates to fill thin walls; Simulate gating with CFD to reduce misruns; Use ceramic foam filters within the gating system.

Green Sand

A mold material of silica sand, clay (bentonite), water, and additives used in sand casting, compacted but not baked.

Adjust moisture to hit green compression strength; Mull longer to improve green sand consistency; High LOI in green sand causing gas defects.

HBI (Hot Briquetted Iron)

A compacted form of direct reduced iron with improved density and handling characteristics for steelmaking charges.

Increase HBI in the EAF charge to control residuals; Compare HBI and DRI pricing; HBI improves logistics versus cold DRI pellets.

Heat Treatment

Thermal processing (heating, holding, cooling) to change microstructure and properties, including processes like normalizing, quenching, tempering, and aging.

Apply T6 to aluminum castings for strength; Normalize and temper steel castings; Stress relieve large iron castings to reduce distortion.

Hot Tearing

Cracks that form during the final stages of solidification due to thermal contraction stresses and restraint.

Hot tears observed at sharp fillets; Add chills and redesign feeders to reduce hot tearing; Simulation highlights high hot-tear risk zones.

Inclusions

Nonmetallic particles (oxides, sulfides, slag, sand) entrained in the metal that degrade mechanical properties and leak tightness.

Oxide inclusions caused leak failures; Install filters to capture bifilms; Inclusion ratings improved after flux optimization.

Inoculation

The addition of materials (e.g., ferrosilicon) to molten cast iron to promote nucleation, refine graphite, and control chill and microstructure.

Late-stream inoculation improved chill depth; Control inoculant addition rate and fade; Use FeSi inoculant with rare earths for thin sections.

Investment Casting

The lost-wax casting process that creates precise, near-net-shape components by building a ceramic shell around a sacrificial wax pattern.

Use investment casting for turbine vanes with thin walls; Build ceramic shells with 7–9 dips; Wax pattern dimensional control critical to tolerance.

JIT (Just-in-Time)

A production and inventory strategy that supplies materials and parts exactly when needed to reduce inventory and waste.

Implement JIT deliveries of sand cores; JIT reduced WIP and floor space; Risk to JIT from supplier variability and transport delays.

Jobbing Foundry

A foundry focused on low-volume, high-mix castings, often with frequent setup changes and diverse alloys and mold types.

Jobbing work requires flexible tooling and quick changeovers; Quote variability is high in a jobbing foundry; Invest in 3D-printed cores for jobbing responsiveness.

Kaizen

A philosophy and practice of continuous, incremental improvement involving all employees.

Run a kaizen event in the melt shop to reduce delays; Daily kaizen board tracks small improvements; Kaizen blitz cut changeover time by 40%.

KPI (Key Performance Indicator)

Quantifiable measures that track performance against strategic and operational goals.

Core KPIs include OEE, scrap rate, and casting yield; Weekly KPI review drives accountability; Tie operator bonuses to safety and quality KPIs.

Ladle Metallurgy

Refining and adjustment of molten metal chemistry and cleanliness in the ladle after tapping the furnace.

Perform argon stirring and trimming additions in the ladle; Desulfurize in-ladle before teeming; Control ladle slag basicity to avoid reoxidation.

Lean Manufacturing

A methodology to maximize value and minimize waste through flow, pull, standard work, and continuous improvement.

Apply 5S to the fettling area; Map the value stream for coremaking; Introduce kanban for molding sand and binders.

LME (London Metal Exchange)

A global marketplace for trading base metals and setting benchmark prices used in contracts and hedging.

Hedge aluminum exposure on the LME; Price surcharges tied to LME cash price; Monitor LME warehouse stocks to gauge supply tightness.

MSA (Measurement System Analysis)

A set of statistical tools to evaluate the accuracy, precision, and stability of measurement systems.

Conduct gage R&R on the CMM for bore diameter; MSA showed measurement bias on hardness tester; MSA is required for PPAP approval.

MT (Magnetic Particle Testing)

A nondestructive method for detecting surface and near-surface discontinuities in ferromagnetic materials using a magnetic field and ferrous particles.

Perform wet fluorescent MT on safety-critical castings; Use longitudinal magnetization for axial cracks; Demagnetize parts after MT inspection.

Mold Hardness

A measure of the compacted sand mold’s surface strength, affecting dimensional accuracy, penetration, and surface finish.

Achieve mold hardness of 85 B-scale to prevent penetration; Uneven hardness caused fins on the cope side; Adjust squeeze pressure and sand moisture to tune hardness.

NDT (Nondestructive Testing)

A family of inspection techniques (e.g., RT, UT, PT, MT) that evaluate integrity without damaging the component.

NDT plan includes RT for wall-thickness sections and UT for central soundness; Require Level II certification; Audit NDT coverage for safety-critical parts.

No-Bake Binder System

A self-setting sand system using liquid resins and catalysts that cures at room temperature, suited for large molds and complex cores.

Switch large castings to no-bake molds; Optimize binder percentage to balance strength and shakeout; Capture VOC emissions from no-bake coremaking.

Nodularity (Ductile Iron)

The percentage of graphite present as spheroids in ductile iron, strongly influencing mechanical properties.

Maintain nodularity above 90% for fatigue resistance; Low nodularity traced to high sulfur; Confirm nodularity on wedge test samples.

OEE (Overall Equipment Effectiveness)

A composite metric of equipment performance based on availability, performance rate, and quality yield.

OEE improved from 58% to 72% on the molding line; Availability losses from unplanned downtime hurt OEE; Use OEE to prioritize maintenance and SMED.

OEM (Original Equipment Manufacturer)

A company that designs and assembles end products and buys cast components from foundries or suppliers.

Align PPAP timing with OEM program milestones; OEM audit reviewed our APQP and QMS; OEM-directed material change requires requalification.

OPEX (Operating Expenditures)

Ongoing costs of running the business (e.g., energy, labor, consumables), distinct from capital expenditures.

Natural gas and electricity dominate melt shop OPEX; Track OPEX per ton poured; Cut OPEX by improving yield and reducing scrap.

PPAP (Production Part Approval Process)

A customer approval process (especially in automotive) that verifies the supplier’s process can consistently produce conforming parts at the quoted rate.

Submit PPAP Level 3 with dimensional layout and capability studies; Annual PPAP revalidation required by the OEM; PPAP failed due to inadequate MSA results.

QMS (Quality Management System)

The organizational structure, processes, and documentation to ensure consistent product quality and continual improvement, often certified to ISO 9001 or IATF 16949.

Pass the ISO 9001 surveillance audit; Control plan and document control are core QMS elements; Use corrective action within the QMS to address audit findings.

Riser

A reservoir attached to a casting that feeds liquid metal as the part solidifies and shrinks, preventing internal voids.

Add an exothermic sleeve to the top riser; Riser neck was undersized, causing shrinkage porosity; Use blind risers with insulating sleeves for better yield.

SPC (Statistical Process Control)

The use of statistical methods to monitor and control processes, aiming to maintain stability and improve capability.

Chart pouring temperature with X-bar/R; Cpk improved after sand moisture control; Set SPC alarms on core dimensional data.

UT (Ultrasonic Testing)

A nondestructive inspection method using high-frequency sound waves to detect internal defects and measure thickness.

UT indicated lack of soundness at the hub center; Calibrate UT for the alloy and thickness; Use phased array UT for complex geometries.