An Allen wrench, AKA an Allen key or hex key, is a small hand tool used to fasten screws or bolts with a hexagonal socket ... Place one end into the head of the hex fastener and turn with the ...

Gray’s new 3/8-in. drive socket set (part no. 25016-I) includes seven SAE hex head sockets, ranging from 1/8 to 3/8 in., as well as seven metric hex head sockets from 4 to 10 mm. Also included ...