Pinchbeck (alloy) it came to mean a cheap and tawdry imitation of gold. Pinchbeck is typically composed of copper and zinc in ratios of 89% copper to 11% zinc; or 93% copper to 7% zinc. Pinchbeck (alloy) Pinchbeck is a form of brass, an alloy of copper and zinc, mixed in proportions so that it closely resembles gold in appearance. It was invented in the 18th century by Christopher Pinchbeck, a London clockmaker. Since gold was only sold in 18-carat quality at that time, the development of pinchbeck allowed ordinary people to buy gold 'effect' jewellery on a budget. The inventor allegedly
Brass desired form and size. The general softness of brass means that it can often be machined without the use of cutting fluid, though there are exceptions to this. Aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of aluminium oxide (AlO) to be formed on the surface that is thin, transparent and self-healing. Tin has a similar effect and finds its use especially in seawater applications (naval brasses). Combinations of iron, aluminium, silicon and manganese make brass wear and tear resistant. To enhance the machinability of brass, lead is often added in concentrations of