Shoulder screws, also known as shoulder bolts or stripper bolts, are fasteners characterized by a smooth, cylindrical shoulder between the head and threads. The shoulder allows for precise positioning, rotation, and sliding of connected parts, making them ideal for applications like machinery, tools, and automotive components. Their design enables parts to move or pivot without binding, enhancing functionality in dynamic assemblies. Common uses include hinges, pulleys, and sliding mechanisms.

Unlike regular screws, which have continuous threads, shoulder screws have a distinct unthreaded section called the "shoulder." This shoulder ensures a fixed diameter for precise alignment and movement of parts. Regular screws are primarily used for clamping and holding materials, while shoulder screws support rotational or sliding actions. The smooth shoulder often serves as a guide or bearing surface in mechanical setups.

Shoulder screws are typically made from materials like stainless steel, alloy steel, and brass, chosen based on application needs. Stainless steel offers corrosion resistance, making it suitable for outdoor and marine use. Alloy steel provides strength for heavy-duty applications, while brass is used for aesthetics and non-magnetic properties. Some are coated or treated for added durability.