The 17-4 PH stainless steel shoulder screw has a plain finish and a socket cap head with hex socket drive, and meets American Society of Mechanical Engineers ASME B18.3 specifications. The 17-4 PH stainless steel material provides good corrosion resistance and high strength. The material may be slightly magnetic. The socket cap head is round with a flat top and a high profile that provides high strength, and installs using an internal drive system that enables more compact spacing than a hex head cap screw. The hex socket drive has a hexagonal slot that requires an Allen key driver, also known as a hex key or Allen wrench.
Shoulder screws, also known as shoulder or stripper bolts, have a smooth unthreaded shaft that acts as a spacer or bearing surface between the threaded portion and the screw head. Shoulder screws with round shafts are commonly used for items that require rotation, while those with square shafts are typically used to lock into place and prevent rotation.