Copper
Copper Compositions / Mechanical Properties

Brass Sheet and Plate
(Brass and Gilding Metal)

The most popular brass for general and electrical engineering purposes is CZ108, the 63/37 "common" brass. This has excellent strength, hardness, ductility and corrosion resistance. It is easily joined by soft or hard (silver) soldering, but care should be taken when brazing due to the closeness of melting point of the filler alloy. If likely to be exposed to corrosive environments after extensive cold work, it should be stress-relief annealed at 250° C - 350° C in order to reduce the tendancy for stress corrosion.

CZ106, the 70/30 or "Cartridge" brass has a higher copper content and is therefore slightly more expensive than CZ108. It does have advantages of even better ductility, which makes it excellent for heavy stamping and deep drawing operations, and a reduced susceptibility to stress corrosion cracking.

The Gilding metals, as their name implies, have a very pleasing durable appearance and are much used for decorative purposes as well as for general engineering. Deep drawability is excellent.

Specifications
BS 2870 for Sheet, Strip and Foil
BS 2875 for Plate

As shown in BS 2870, the brasses and gilding metals are available in a wide variety of tempers from annealed through 1/4 hard, 1/2 hard to hard, extra hard and spring hard.

Engraving Quality Brass
We hold a stock of CZ120 to BS 2870 in the thickness range 20G to 1/4 (weights as per tables). This lead bearing brass ensures clean easy cutting to close tolerances. Apart from engraving it is also used for precision clock and instrument parts. Available in plain or polished finishes.

Naval Brass
For use in Brackish waters, seawater and other aggressive environments. Tin is added to brass to give a significant improvement in corrosion resistance. Strength is higher and therefore reccomended for the manufacture of pipe fittings and similarly heavy-duty applications.

Machinability is not as good as free machining brass, but still easier than stainless steels. Can be hot stamped.

We offer a full cutting and shaping service to provide straight line cutting as well as circles, rings, and irregular shapes.

Specifications
BS 2872 for Forging Stock
BS 2874 for Rod, Bar and Hollow Section
BS 2870 for Sheet
BS 2875 for Plate

Compositions / Mechanical Properties

Copper-Nickel Alloys
These alloys (sometimes called cupro-nickels) have nickel contents ranging from10% to 45 %, often with small additions (0.5% - 2.0%) of iron and/or manganses

The overiding qualities are a combination of good cold and hot working properties, superlative sea water corrosion and erosion resistance and good strength. Typical users are thus sea water distilation and desalination plant, marine condensers etc. where long trouble free performance is rated more highly than initial cost.

The two alloys most commonly used for these applications are CN102 (10% nickel) and CN107 (30% nickel) - both with small amounts of iron and manganese.

One other copper-nickel alloy is of interest (and value) to us all. It is the alloy CN105, which is 75/25 copper nickel with a small addition of manganese. The main user is the Royal Mint!

The 90/10 alloy is primarily used for sea water piping aboard shipsm and for the very large seawater piping systems on offshore oil production platforms.

Both of the copper nickel alloys have applications in the handling of hot brines, they are frequently employed in condenser and heat exchangers for tubes, tube plates and baffles where resistance is required to salt-water corrosion, erosion, impingement and biological fouling.

Copper-nickel is available in most product forms, including plate, tube, pipe and fittings. Plate is available in any cut size on short delivery.

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