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
British Standard Brass of the tube or cut right through it. Brass tube threads can be confused with the British Standard Cycle thread, one of which that is most common is also 26 tpi. The difference being the thread angle of the British Standard Cycle is the same as the metric thread angle of 60 degrees. Nominal sizes are usually in the range to 2 inches. British Standard Brass British Standard Brass or British Brass Thread is an imperial unit based screw thread. It adopts the Whitworth thread form with a pitch of 26 threads per inch and a thread angle of 55