The Hillman Group 2771 5/16 x 2-1/2-Inch Automotive Stud, 5-Pack
Automotive studs are a headless bolt that is threaded at both ends, the center portion being unthreaded. An automotive stud is used to insert one end into the head or block and then insert a nut or washer on the other end. For example, bolting the exhaust manifold to the head.