Metal Glossary

Admiralty Brass

A nominal 70% Copper / 30% Zinc Brass with 1% Tin added to improve corrosion resistance.

Alloy

A combination of two or more metals, or of metals and other elements. An alloy is formed by adding the 'alloying elements' to the 'parent' metal in the molten state. The parent metal usually accounts for more than 50% of the resultant mixture. Brass is an alloy of Copper and Zinc whilst Bronze is an alloy of Copper and Tin.

Alpha Brass

A Brass whose microstructure consists only of the 'alpha phase' in which the Zinc is in solid solution within the Copper matrix. This occurs in the range from pure Copper to about 64% Copper - 36% Zinc. Alpha Brasses have good cold-working properties.

Alpha-Beta Brass

A Brass containing over 36% Zinc, or with other additions, that has both alpha and beta phases present in its microstructure.

Related terms: Duplex Brass

Aluminium Bronze

Not true Bronzes as they contain no Tin, Aluminium Bronzes are alloys of Copper with 5 - 12% Aluminium, some having additions of Iron, Nickel, Manganese and Silicon. They are available in cast and wrought form with designations such as CA104, Defence Standard (NES) 83. Aluminium Bronzes combine high strength with excellent corrosion and shock resistance. Widely used for stressed components in corrosive environments they are, in particular applications, frequently technically sound, cost effective, alternatives to Stainless Steels and Nickel Alloys.

Annealing

Full Annealing is a heat treatment process for fully softening Copper and Copper Alloys. It involves heating to 500-550oC and holding for an appropriate time. Partial annealing is used to leave some residual temper such as quarter hard or half hard.

Architectural Bronze

A confusing, loose, but widely used term used to describe a number of brasses. • Those, whose colour mimics that of Bronzes, that are used in architectural applications, such as decorative shop fittings, window frames, etc, • The Manganese containing brass CZ136, which is also incorrectly called Manganese Bronze, is a High Tensile Duplex Brass which extrudes well and has a warm 'chocolate' colour. • The term is also applied to Gilding Metals which have been chemically toned to give a 'bronze' finish.

Related terms: Manganese Bronze

Arsenical Brass

A 70% Copper/30% Zinc alpha brass that contains Arsenic, and frequently Aluminium. It has better corrosion resistance than cartridge brass, but similarly excellent forming properties.

ASTM

The American Society for Testing and Materials. ASTM produces Standards for materials and test methods that are widely used other than in the USA.