Glossary

A shoulder bolt—also known as a shoulder screw or stripper bolt—is a fastener with three distinct sections: a head, a precisely machined unthreaded shoulder, and a smaller-diameter threaded portion. The shoulder portion is larger in diameter than the threads and is manufactured to tight tolerances, allowing it to function as a precision pivot, spacer, guide, or bearing surface, rather than purely as a clamping fastener.

The defining feature of a shoulder bolt is the smooth cylindrical shoulder, which provides a low-friction surface for components to slide, rotate, or accurately position relative to each other. Because the shoulder carries shear loads and controls alignment, the threads typically engage only at the end of the bolt, allowing the joint to be tightened without restricting movement on the shoulder itself.

Shoulder bolts are used extensively in machinery, tooling, automotive assemblies, robotics, and manufacturing equipment—anywhere components must rotate, slide, hinge, or align. They are common in punch-and-die setups, pulleys, cams, linkages, linear guides, and moving mechanical assemblies. They are often made from alloy steel or stainless steel and may have hex socket heads for precise torque control.

AKA: Shoulder Screw, Stripper Bolt