Shoulder bolts are specialized fasteners designed with a cylindrical shoulder that provides a precise bearing surface. This unique design allows for smooth rotation and movement, making them ideal for applications requiring pivoting or sliding actions. They are commonly used in machinery, automotive components, and various mechanical assemblies. These bolts come in various sizes and materials, including steel, stainless steel, and plastic. The shoulder diameter is larger than the threaded portion, which helps to distribute load and reduce wear. Proper installation ensures optimal performance in applications such as hinges, linkages, and joints.