Aluminum and aluminum alloys are lightweight, non-ferrous metals with good corrosion resistance, ductility and strength. Products differ in terms of composition, grade, shape, dimensions, and features. Commercially pure, unalloyed, or very low alloy aluminum does not contain or contains only very small amounts of alloying elements. By contrast, aluminum alloys contain significant amounts of added elements or constituents. Clad or bimetal stock consists of two different alloys that are bonded integrally together. Metal matrix composites have a composite or reinforced metal or alloy matrix filled with a second component, which may be in particulate, chopped fiber, continuous filament, or fabric form. Other unlisted, specialty or proprietary aluminum and aluminum alloys are also available. These materials are often based on a unique alloy system, use a novel processing technology, or have properties tailored for specific applications.    

Aluminum and aluminum alloys meet the compositional standards of the Unified Numbering System (UNS), a specification established by the American Society for Testing and Materials (ASTM), the Society of Automotive Engineers (SAE), and metal trade associations such as the American Iron and Steel Institute (AISI). The UNS assigns metals and alloys a lettered prefix and a five-digit number. Aluminum and alloy steels belong to the UNS A category and have designations such as UNS A15350. Aluminum Association (AA) grades are another common specification for aluminum and aluminum alloys. Other standards include casting grades, European Norm (EN), American Society of Mechanical Engineers (ASME) standards, and U.S. military specifications (MIL-SPEC). QQ and QQS prefixes are used to designate specific MIL-SPEC metals. 

Aluminum and aluminum alloys are lightweight, non-ferrous metals with good corrosion resistance, ductility and strength. Products differ in terms of composition, grade, shape, dimensions, and features. Commercially pure, unalloyed, or very low alloy aluminum does not contain or contains only very small amounts of alloying elements. By contrast, aluminum alloys contain significant amounts of added elements or constituents. Clad or bimetal stock consists of two different alloys that are bonded integrally together. Metal matrix composites have a composite or reinforced metal or alloy matrix filled with a second component, which may be in particulate, chopped fiber, continuous filament, or fabric form. Other unlisted, specialty or proprietary aluminum and aluminum alloys are also available. These materials are often based on a unique alloy system, use a novel processing technology, or have properties tailored for specific applications.    

Aluminum and aluminum alloys meet the compositional standards of the Unified Numbering System (UNS), a specification established by the American Society for Testing and Materials (ASTM), the Society of Automotive Engineers (SAE), and metal trade associations such as the American Iron and Steel Institute (AISI). The UNS assigns metals and alloys a lettered prefix and a five-digit number. Aluminum and alloy steels belong to the UNS A category and have designations such as UNS A15350. Aluminum Association (AA) grades are another common specification for aluminum and aluminum alloys. Other standards include casting grades, European Norm (EN), American Society of Mechanical Engineers (ASME) standards, and U.S. military specifications (MIL-SPEC). QQ and QQS prefixes are used to designate specific MIL-SPEC metals. 

Suppliers provide aluminum and aluminum alloys in many stock shapes and forms. Semi-finished stock shapes are suitable for part fabrication by machining, assembly, or other processes. They are also used as feedstock for casting, forging, and spinning. Common stock shapes and forms for aluminum and aluminum alloys include bars, rods, tubes, plates, profiles, sheets, strips, shims, spheres, foil, wire, billets, slabs, and blooms. Materials are also supplied as billets, ingots, powders, fillers, and reinforcements. Round, hexagonal, coil, and hollow stock are also available. There are two basic types of anodes. Plating anodes are in used in plating or electroplating processes. Sacrificial anodes are used to protect stainless steel or other metal structures from corrosion.  

Selecting aluminum and aluminum alloys requires an analysis of dimensions, production processes, and performance features. Outer diameter (OD), inner diameter (ID), overall length, and overall thickness are important dimensions. Most materials are cast, wrought, extruded, forged, cold-finished, hot-rolled, or formed by compacting powdered metals or alloys. Performance features for aluminum and aluminum alloys include resistance to corrosion, heat, and wear. Cold worked metals have good compressive strength and wear resistance under room temperature conditions. Free-machined metals contain lead, selenium, or sulfur additives.