Brass

For purposes of identification, copper and copper alloys are divided into characteristic groups, each group determined by its composition, and referenced by a system of three-digit numbers originally designated by the Copper Development Association, or CDA. Today, these designations have been expanded to five digits, following a prefix letter 'C', and made a part of the Unified Numbering System for Metals and Alloys (UNS), which is jointly managed by the American Society for Testing and Materials (ASTM) and by the Society of Automotive Engineers (SAE).

100 Series (C10000) Coppers

This group comprises the pure coppers, those with a designated minimum copper content of 99.3%, for high electrical conductivity.Also included within this group are the high copper alloys, those withcopper contents of between 99.3% and 96%; which contain additionalalloying elements such as beryllium, cadmium,chromium, cobalt, nickel, or iron forgreater strength without drastically reducing the electrical conductivity.

200 Series (C20000) Brasses

These are the basic copper-zinc alloys which feature ease of manufacturing while still maintaining fair electrical characteristics. These alloys are excellent for drawing and forming while still providing good strength.

300 Series (C30000) Leaded Brasses

These are basically brass alloys that contain an addition of 1 to 3% lead to provide greater ease of machining, blanking, shearing, sawing, and milling.

400 Series (C40000) Tin Brasses

These alloys contain 1 to 2% of tin as well as copper and zinc to provide greater corrosion resistance while maintaining strength. These alloys find many uses in electrical applications such as contact springs, fuse clips, terminals, and connectors.

500 Series (C50000) Phosphor Bronzes

These alloys feature greater resistance to alternating or cyclic stress as required in applications for springs, diaphragms, bellows, and contacts. This series also includes the leaded phosphor bronzes which provide better performance under load conditions found in sleeve bushings, bearings, thrust washers, and engine and drive train applications.

600 Series (C60000) Bronzes

This series of alloys includes the aluminum bronzes, which contain 2 to3% of aluminum for strength while maintaining formability. These alloys are often used for wear plates, bushings, bearings, and hydraulic valve parts. Also included in this group are the silicon bronzes which are suitable for all types of welding in addition to having good hot-forming and cold-working properties. Other miscellaneous copper-zinc alloys are also included within this classification series.

700 Series (C70000) Nickel Silvers

These special alloys composed of copper, nickel, and sometimes lead, have high strength and increased resistance to corrosion along with good formability.