SOCKET WRENCH

A socket wrench is made up of a ratchet and a variety of sockets. The ratchet end fits into the sockets. The end is usually one of three common sizes: 0.25" (6.35 mm), 0.375" (9.5 mm), and 0.5" (13 mm). The socket (a cylinder) completely covers all the corners of the head of a bolt or nut. Some sockets have six faces while others have twelve.