Precision Shoulder Screws

Shoulder screws are different from regular machine screws in a variety of ways. In appearance, the unthreaded shank (or shoulder) portion is larger than the thread diameter. The difference between the two is usually on the order of one so that, for instance, a 38” diameter shoulder will be accompanied by a 516” thread. The larger diameter shoulder allows for greater shear strength across that unthreaded portion and permits its use in a wide variety of applications, including pulley attachment, heavy machinery support and motion guiding. When describing a shoulder screw, the diameter and length of the shoulder are the primary dimensional characteristics. The heads are usually round and knurled. The standard drive types are hex socket.