3/16 Long Arm Alloy Steel Hex Key supports the socket-screw system by matching a 3/16 in. width across flats to the working tool. The ASME B18.3 width band is 0.1860-0.1875 in.; the key is held just under nominal so it enters an in-tolerance socket and bears on the flats.
Heavy equipment and large socket cap screws at the upper end call for wider keys that are harder to restock loose. Long Arm geometry adds reach and leverage; the same width in Short Arm form is the natural compact comparison.
Since 1962, Cold Headers has supplied specialty socket hardware and the hex keys that complete the working system. Review the 3/16 in. width, Long Arm format, short-leg length, and arm length before ordering. For a non-catalog width or series, Cold Headers can help confirm the request before quoting.
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
