Founded in 1938, Standard Lock Washer & Mfg is a domestic manufacturer of special nuts in hex/square/round bar stock. Based in Worcester, Mass., the company manufactures and stocks the complete range of taper pin sizes, both plain and threaded, in steel and stainless steel. Standard Lock Washer & Mfg. is also a distributor of flat washers, tooth lock washers, split lock washers, helical spring lock washers, woodruff keys, dowel pins, cotter pins, spring/split pins and fastener assortments. The company is an approved vendor for Rosemount Nuclear Instruments, B.F. Goodrich Aerospace, Anixter-Pentacon Aerospace, Wurth/Adams/Snider/Service Supply, Achilles Aerospace, etc.