Casting Industry Glossary - Harmony Castings

Industry Glossary

The casting industry has a lot of terms that may be difficult to understand. This Glossary is here to help you understand more about the casting industry and what the terminology means.

Aging: A gradual change in the properties of a metal or alloy over time, often accelerated by elevated temperatures.

Allowance (Tolerance):The specified difference between mating part dimensions,defining minimum clearance or maximum interference.

Alloy: A metallic material made from two or more elements, at least one of which is a metal, with properties that differ from its individual components.

As Cast: A casting in its original state, without heat treatment, machining, coating, or other finishes.

BHN: Brinell Hardness Number.

Blasting (Blast Cleaning): Cleaning or finishing a surface by propelling abrasive media such as grit or shot against it.

Brinell Hardness: A quantitative measure of a material’s resistance to deformation, scratching, or penetration from an external force.

Brittle Fracture: A break that occurs with little or no plastic deformation.

CAD: Computer Aided Design.

CAE: Computer Aided Engineering.

CAM: Computer Aided Manufacturing.

Cavitation: The formation and collapse of bubbles or voids within a liquid.

CMM:Coordinate Measuring Machine.

CNC: Computer Numerical Control machine tools.

Coefficient of Expansion: The amount a material changes in size for a given change in temperature.

Compressive Strength (Yield): The maximum compressive stress a material can withstand before permanent deformation or failure.

Contraction: The reduction in volume that occurs as metals cool and solidify.

Cope: The upper section of a pattern.

Core: A shaped insert, usually made of sand used to create internal cavities or features in a casting.

Core Box: A tooling component used to produce sand cores for metal casting. Contains the shape of the desired core and is filled with bonded sand and a binding system to create a hardened core that forms internal cavities, passages, or complex features within a casting.

Crucible: A heat resistant container used to melt metals.

Crucible Furnace: A furnace in which metal is melted inside a refractory crucible.

Datum Points: Reference points used for measurement, layout, or machining operations.

Defect: A flaw that fails to meet specification requirements.

Degasser: A material or agent used to remove dissolved gases from molten metal.

Degassing: The process of removing unwanted gases from molten metal, often through chemical reactions or inert gas injection.

Drag: The lower section of a pattern.

Fatigue: The progressive weakening of a material caused by repeated loading cycles.

Finish Welding: Production welding performed to achieve a required casting quality.

Flask: A frame used to hold or form a sand mold. The upper half is the cope and the lower half is the drag.

Foundry Returns: Scrap metal, gates, risers, and runners returned to the furnace for remelting.

Frictional Wear: Material loss caused by contact and movement between surfaces.

Gating System: The complete network of sprues, runners, and gates that directs molten metal into a mold.

Heat Treatment: Controlled heating and cooling used to improved specific mechanical properties such as strength.

Impregnation: A sealing process used to eliminate leaks in castings by filling pores with a sealing compound.

Impurity: An unintended element present in a metal or alloy that may affect performance.

ISO: International Standardization Organization.

Ladle: A refractory lined vessel used to transport and pour molten metal.

Liquid Penetrant Testing: A nondestructive inspection method used to detect surface defects.

Machine Allowance: Extra material added to a casting to permit final machining such as tabs.

Mechanical Properties: Characteristics that describe a material’s strength, stiffness,ductility, and behavior under load.

Meyer Hardness Test: A hardness test that evaluates a metal’s tendency to work harden under increasing loads.

Mock-Up: A full scale model built for evaluation, testing, or display.

Mold Cavity: The space within a mold that fills with molten metal to form the casting.

Necking: A localized reduction in cross sectional area caused by tensile stretching.

NFFS: Non Ferrous Founders’ Society.

Nondestructive Testing (Inspection): Inspection methods that evaluate a part without damaging it.

Nonferrous: Describes metals and alloys in which iron is not the primary element.

Open Grain Structure: A defect characterized by a coarse, porous appearance, often associated with shrinkage.

Parting Line:The line where the cope and drag sections of a mold separate.

Pattern: A form used to create the mold cavity.

Pattern Draft: A slight taper added to a pattern to allow easy removal from the mold material.

Porosity: Small cavities or voids within a casting caused by gas entrapment, shrinkage,or process variables.

Pouring: The transfer of molten metal into a ladle or mold.

Process Capability: A measure of process variation.

Profile Tolerances: Tolerance limits applied around an ideal profile to control part geometry.

Quenching: Rapid cooling of a material, typically in water or another medium.

Rigging: The gates, risers, and related components required to produce a sound casting.

Riser: A reservoir of molten metal that feeds a casting as it shrinks during solidification.

Riser Gating: A method of directing molten metal through a riser to promote directional solidification.

Runner: A channel that carries molten metal from the sprue to the mold cavity.

Runner Extension: An extension beyond the last ingate that traps dirt and debris before metal enters the cavity.

Runner Riser: A runner large enough to act as both a flow channel and a feeding reservoir.

Runout: A casting defect caused by molten metal leaking from the mold or failing to completely fill it.

Shakeout: The process of separating a casting from the mold material.

Shot Blasting: A cleaning or surface treatment process using propelled metal shot or grit.

Shrinkage: The reduction in volume or dimensions that occurs during cooling, solidification, or heating of certain materials.

Skimming: Removing slag, dirt, or impurities from the surface of molten metal.

Solidification: The transformation of molten metal from a liquid to a solid state.

Sprue Hole: The opening through which molten metal enters the mold.

Temper: Heat treatment used to improve toughness and reduce brittleness, or the moisture condition of molding sand.

Tensile Strength: The maximum tensile stress a material can with stand before fracture.

Tolerance: The allowable variation from a specified dimension.

Toughness: A material’s ability to absorb energy and deform before severe damaging.

Ultrasonic Testing: A nondestructive inspection method that uses high frequency sound waves to detect internal flaws.

Vacuum Forming: The process used in V process molding where a vacuum holds dry sand in place around a plastic film to create a mold.

Vacuum Process (V-Process): A molding process that relies on a vacuum pressure and dry, unbonded sand to create accurate molds.

Wall Thickness: The distance between opposite surfaces of a casting section, which affects cooling rates, strength, and manufacturability.

Warpage: Distortion that develops in a casting during cooling, heat treatment, or service.

Welding, Arc: Welding performed using an electric arc as the heat source.

X-Ray: High energy electromagnetic radiation used for inspection and internal defect detection.

Yield Strength: The stress level at which a material begins to deform permanently.

Zero-Degree Draft: The ability to produce a casting with 90 degree vertical walls

Need More Information?

Whether you're looking for technical guidance, answers to common questions, or helpful videos, our Resource Center has the tools you need to make the most of Harmony Casting's products and services.