Yellow castings

In the past, alloys with 56 to 80 per cent copper used for mould casting were referred to as yellow castings, thus clearly distinguishing them from gunmetal and bronze. The "brass casters" even had their own guild.

Copper contents of 58 % to 60 % distinguish the field of so-called wrought brass alloys from that of cast alloys. The industrially important machining brasses containing lead are classified as wrought alloys. They have a different crystal lattice structure than brass with a Zn content of up to 38.95 % and can contain lead in fine droplets as a chipbreaker.

The lead does not dissolve in the crystal lattice, but is present as a finely dispersed phase. Lead contents vary between 0.5 % and max. 3.5 %. The more lead is contained, the better the material can be machined and the finer the chips produced. More than 3.5 % lead content improves the machinability only slightly, but causes problems when melting the alloy.

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