Sockets

The drive comes first: 1/4″ for small bolts and interior work, 3/8″ for general servicing, 1/2″ for suspension and wheels, 3/4″ and 1″ for trucks and farm machinery. The socket has to fit both the wrench and the bolt.

A 6-point socket grips the bolt on all six flats and does not round the corners; a 12-point one fits into tighter spots and also suits 12-point bolts. An impact socket is hardened steel with a black finish: only that kind may be used on an impact wrench, a standard socket can shatter.

A set pays off once you need more than eight sockets of one drive: the ratchet, the extensions and the universal joint are then included and the case keeps them together.