Shoulder bolts or shoulder screws, have a long, unthreaded, cylindrical shoulder that allows for the rotation of attached parts like pulleys, gears, moving parts of engines and mechanical assemblies, and rolling wheels. A shoulder screw has a smooth shank top, or shoulder, with a narrower, threaded tip at the bottom.
Materials: Alloy Steel, Stainless Steel
Types of Shoulder Bolts:
Socket Shoulder Bolt (ASME B18.3 and ISO 7379)
Slotted Shoulder Bolt
Hex Head Shoulder Bolt