Bolt extraction socket sets are used to remove stuck, rounded, and rusted nuts and bolts. They fit around and bite into and firmly grip the fastener head as the socket is turned. Sockets require a hand drive tool such as a ratchet or breaker bar to turn the socket and rotate the fastener for removal. Drive tools have a square nub called the drive that fits into the same size drive end of the socket for secure attachment to the drive tool. Sets come with an assortment of sockets for a range of fastener head sizes.