Screws DIN 965 Pozi Countersunk Head Screws The outer edge of the head of the hexagon socket screw is round, and the middle is a recessed hexagon. It is usually used with a hexagon wrench. Commonly used in machinery, it mainly has the advantages of easy fastening, disassembly, and not easy to slip corners. Feature and Advantage 1. Made of carbon steel and provides excellent rust resistance. 2....