ForgeFix Hexagon Nut & Nylon Insert ZP - ForgeFix 50NYLOC12, The Forgefix Nyloc hexagon nut is a fastener that incorporates a nylon component to effectively lock the nut into position on the bolt. The nylon component has a smaller inside diameter than the actual nut. This locks the nut in place by squeezing the nylon firmly around the bolt when tightened. Unlike a standard locking washer, the Nyloc nut prevents the nut from loosening under vibration as the nylon is tightly wedged into the bolt threads and provides resistance to turning when tightened. The nuts are zinc-plated for increased resistance to corrosion. Their hexagonal shape is designed to be driven by a wrench (spanner) and provides excellent torque. Where a permanent fastening is required and loosening must be prevented by movement or vibration. Can be used on most bolt products including HT Bolts, Carriage Bolts, Threaded Rod etc. Zinc coatings prevent oxidation of the protected metal to create a longer lasting finish. It