Socket Shoulder Screws

Socket shoulder screws, also known as shoulder bolts, are fasteners with an unthreaded cylindrical section, or shoulder, between threads and screwhead. The shoulder is larger in diameter than the threaded section and provides an axis around which close-fitting moving parts operate. Shoulder screws are available with an undercut shoulder where the diameter of the shoulder can be as small as the minor diameter of the threads. Socket shoulder screws are idnetified by the diameter and the length of the shoulder. Shoulder screws can be produced with head styles other than the typical hex socket head. Socket shoulder screws are also available with tight dimensional tolerances, often referred to as precision shoulder screws. Shoulder screws are available in alloy steel and stainless steel. ASME B18.3