Brass

Brass is an alloy of copper and zinc. It looks like gold, resists corrosion, is easy to cut, stamp and bend, and conducts electricity reasonably well. Those traits put it in plumbing fittings, musical instruments, keys and electrical plugs.

It is made by melting copper and adding zinc, typically about two parts copper to one part zinc, though the mix varies by use. Zinc boils at a lower temperature than copper melts, so it is added carefully to limit losses as fumes. The alloy is cast into bars or slabs, then rolled into sheet, drawn into rod or wire, or forged. Some grades get a little lead, which helps them cut cleanly on a lathe. More zinc makes brass harder and paler; more copper makes it redder and easier to bend cold.

In the Archive, brass shows up where metal must be shaped precisely and carry current. It forms the pins of the power cord's plug, often nickel plated, the end caps of a fuse, and the nail-like current collector running down the middle of an alkaline battery.