HSS bits, also known as high-speed steel bits, are constructed of carbon steel with the addition of additional elements such as chromium and vanadium. This enables them to operate at high drilling rates. 10mm hss drill bits are suitable for drilling iron, steel, and other metals such as brass, copper, and aluminium alloy. 10mm hss drill bits, an abbreviation for high speed steel drill bits, are exceptionally hardwearing and especially well intended for drilling into metal surfaces because they are significantly more resistant to the heat created by rapid speed operation.