The alloy steel set screw with plain finish has a hex socket and knurled cup point, and meets International Organization for Standardization ISO 4029 specifications. Alloy steel is often used in applications where strength is the primary consideration. The hex socket drive has a hexagonal slot that requires an Allen key driver, also known as a hex key or Allen wrench. The knurled cup point has a serrated edge that grips the mating surface with enough power for use in permanent and semi-permanent applications and helps resist loosening due to vibration.
Set screws hold objects in place by use of pressure at the point, and are often used in semi-permanent applications and where fine adjustment is needed. Set screws are available with a variety of point styles, which determine how the screw interacts with the object it is placed against. These threaded fasteners typically do not have an external head.