You need the Craftsman 18 mm deep socket for turning nuts onto bolts when the bolt extends upward into the socket. Deep sockets can also give you a little extra reach when tightening or loosening a stubborn nut or bolt. This deep socket is made with easy-to-read markings that increase visibility even in low light. Craftsman builds tools to last and this socket is made with quality alloy steel with a 3/8 inch drive. For the same amount of power and grip with a little extra reach and functionality, look toward the Craftsman 18 mm deep socket.