A set of material specifications developed for the aerospace industry.
Annealed
A process of heat treating to soften metal, relieve internal stresses, and improve machinability and formability. This makes the material easier to cut, bend, or machine than hardened material.
ASTM (ASTM International)
An organization that publishes industry standards covering the composition, properties, testing, and manufacturing of metals and thousands of other materials.
Austenitic
A classification for a group of stainless steels. Austenitic steels have excellent corrosion resistance and toughness and are generally non-magnetic when annealed.
CAGE / DUNS / NAICS
CAGE (Commercial and Government Entity): A unique identifier assigned to organizations that do business with the U.S. government.
DUNS (Data Universal Numbering System): A business identification number historically used to identify individual businesses.
NAICS (North American Industry Classification System): A classification system that identifies a company’s primary business activity, such as metal distribution or manufacturing.
Carburization
A heat treatment process that adds carbon to the surface of steel. It creates a hard, wear-resistant outer layer while maintaining a tougher interior.
Centerless Ground
Material that has been precision ground while supported between a grinding wheel and a regulating wheel rather than being held between centers. Centerless grinding can improve the diameter, roundness, dimensional tolerance, and surface finish of round bar or tubing.
Chamfered
Having an angled or beveled edge where two surfaces would otherwise meet at a sharp corner. Bar ends are often chamfered to remove sharp edges and make the material easier to insert into machinery, fixtures, or other components.
Cold Drawn (CD)
Metal that has been pulled through a die at room temperature to reduce its size and improve its dimensional accuracy and surface finish. Cold drawing typically increases the material’s strength and hardness.
Cold Worked
Metal that has been shaped or strengthened at or near room temperature. Cold working increases strength and hardness but usually reduces ductility.
DFARS / DPAS
DFARS (Defense Federal Acquisition Regulation Supplement): Procurement regulations used by the U.S. Department of Defense. Certain DFARS requirements address specialty metals, material sourcing, and other requirements for defense-related purchases.
DPAS (Defense Priorities and Allocations System): A U.S. government program that requires suppliers to prioritize certain contracts that support national defense and emergency preparedness.
Die
A specialized tool used to cut, shape, form, draw, or extrude material into a specific size or shape. For example, metal can be pulled through a die during cold drawing to reduce its diameter.
Ductile
A metal’s ability to bend, stretch, or deform without breaking. A highly ductile metal is less likely to crack when formed or shaped.
EDM (Electrical Discharge Machining)
A machining process that uses controlled electrical sparks to remove metal. EDM can produce precise shapes, holes, or features in hard or difficult-to-machine electrically conductive materials.
Electro-Slag Remelting (ESR)
A secondary melting process that improves metal cleanliness by removing impurities and reducing internal defects.
Ferritic
A classification for a group of stainless steels. Ferritic stainless steels primarily contain chromium with little to no nickel, are generally magnetic, and offer good corrosion resistance.
Free Machining
A term used for alloys that have been specifically modified to machine more easily than standard grades. They often contain additives such as sulfur or selenium to improve machinability.
Heat Treatment
The controlled heating and cooling of metal to change its mechanical properties, such as hardness, strength, toughness, or ductility, without significantly changing its shape.
Hot Rolled (HR)
Metal that has been rolled or formed at a high temperature. Hot-rolled material is generally less dimensionally precise and has a rougher surface than cold-finished material, but it is often less expensive to produce.
Metallurgical
Relating to the science and technology of metals, including metal composition, structure, manufacturing processes, heat treatment, and mechanical properties.
Molding / Injection Molding
A manufacturing process in which heated or molten material is forced into a mold and allowed to cool or solidify into a specific shape. Injection molding is commonly used with plastics. Metal Injection Molding (MIM) uses fine metal powder combined with a binder, which is molded and then processed to produce the finished metal component.
NADCAP (National Aerospace and Defense Contractors Accreditation Program)
An industry-managed accreditation program for companies performing special processes such as heat treating, welding, non-destructive testing, chemical processing, and materials testing for the aerospace and defense industries.
Pitting
A localized form of corrosion that creates small holes or cavities in a metal’s surface. Pitting can occur due to exposure to chlorides, salts, or other harsh environments.
Precipitation Hardening
A heat treatment process that significantly increases the strength and hardness of certain alloys by forming tiny particles within the metal’s structure.
RoHS / REACH
REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals): A European Union regulation that controls the use of certain chemical substances in products and manufacturing. It is designed to protect human health and the environment.
RoHS (Restriction of Hazardous Substances): A European Union directive that restricts the use of certain hazardous materials, such as lead, mercury, and cadmium, in electrical and electronic equipment.
Temper
A designation of a metal’s condition indicating certain mechanical properties, such as hardness, strength, or ductility. A temper may result from heat treatment, cold working, or a combination of processes.
Tensile Strength
The maximum pulling stress a material can withstand before breaking.
Tolerance
The allowable variation from a specified dimension, property, or requirement. For example, a 1.000-inch diameter with a tolerance of ±0.005 inch may measure from 0.995 to 1.005 inches and still meet the requirement.
UNS (Unified Numbering System)
A standardized identification system for metals and alloys. Each alloy is assigned a UNS designation, such as S45500 for 455 stainless steel or C17200 for Alloy 172 beryllium copper.
Vacuum Arc Remelted (VAR)
A secondary melting process performed under vacuum to produce exceptionally clean, homogeneous metal with fewer impurities and internal defects.
