Socket shoulder cap screws are often called shoulder bolts or shoulder screws due to the key component that sets them apart from the socket product family- the shoulder. A socket shoulder screw has a raised cylindrical head that is often knurled, the same head design as found in socket head cap screws. Installation is completed the same too with a hexagon drive tool, such as a hex key. The hexagon drive is advantageous for those installations with limited space, allowing a user to apply the appropriate torque using a standard Allen wrench. Directly below the bolt head is the key element, an unthreaded section or the shoulder. Lastly, a threaded shaft is found at the far end of the bolt. Socket shoulder screw sizing will look strange compared to standard threaded fasteners as there are extra details listed. The diameter first called out is that of the unthreaded shoulder (D), next is the diameter and pitch of the threaded shaft (D1), and finally the length of the shoulder (L). You'll notice that socket shoulder screws do not list the full length of fastener from head to end, as is common for threaded fasteners.
Fasteners Etc. Inc. offers standard socket shoulder cap screws in steel with thermal black oxide coating and stainless steel. Class 12.9 metric socket shoulder cap screws are available in steel with thermal black oxide coating. Lastly, socket shoulder cap screws are offered with nylon patch or pellets as well. If the shoulder bolt you need is non-standard and not listed as avilabale, we will be happy to provide you a custom quote!
