Standard 20mm single Hex 1/2"drive socket. The six-sided socket head drives from the flats to provide more torque, useful for freeing seized nuts & bolts, whilst avoiding the risk of rounding. The socket has slightly convex internal faces and drilled out corners, for a solid grip, even on damaged fastener heads. Manufactured from durable chrome vanadium steel with a polished finish. Part of a range of individual standard sockets available in a variety of metric sizes from 10mm to 32mm.