Brass

Brass is slightly harder than pure copper, but not as hard as bronze (copper-tin alloy). Unlike steel and aluminium alloys, brass cannot be hardened by heat treatment. 

Characteristic properties are high strength, ductility, cold work hardening, corrosion resistance and good sliding properties. Furthermore, most brass alloys are good conductors of electricity.
 

Brass is a non-ferrous metal consisting of copper and zinc (copper-zinc alloy). Most compounds contain a zinc content of 5% to approx. 45%. 

Brass is the most widely used copper alloy. The European Standards list around 60 grades of brass with different zinc contents. Depending on the copper-zinc mixture ratio, it is not only the properties that change, but also the colour of the metal. One of the most common alloys is CuZn37 with a zinc content of 37%.

 Other common grades are:

• Tombac or gold-brass: Brass alloys with a copper content of more than 70%
• Special brass: Copper-zinc alloy with additional alloying elements, such as aluminium, iron, manganese or tin, also referred to as multi-material alloy.
• Machining or free-cutting brass: Contains lead for enhanced machinability.

Further brass groups depending on the type of processing include:

Cold-formed brass  

This brass grade usually consists of the two alloying elements copper and 5% to 37% zinc. The group is characterised by its good malleability. Copper and zinc mix optimally when molten and remain evenly distributed in the metal even when solidifying. The result is a very homogeneous structure.  

Cold-formed brass is highly suited to the production of brass semi-finished products such as strips and sheets, while it can also be used to produce wire and thin-walled tubes. The basic strength can be increased through cold forming, for example by rolling, forging or drawing. Products made of cold-formed brass are therefore available in both very soft and spring-tempered versions. Furthermore, semi-finished products made of cold-formed brass exhibit an excellent surface quality.

Hot-formed brass

Unlike cold-formed brass, this grade contains a zinc content of over 37%, which creates a heterogeneous microstructure. This type of brass is particularly suitable for hot forming, for example by means of extrusion - bringing it very close to the desired final dimension. Brass tubes, brass rods, brass wires and brass profiles are fabricated from hot-formed brass.

Cast brass 

This brass grade contains additional alloying elements such as aluminium or silicon to increase its suitability for mould casting. The material demonstrates only minimal segregation and a highly homogeneous structure when solidifying. It is suitable for the cost-effective production of brass parts in large quantities, because the end products are almost entirely produced in a single step. At most, it is necessary to machine the surface.