The Forgefix Nyloc Hexagonal Nuts are made from A2 stainless steel and incorporate 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. Their hexagonal shape is designed to be driven by a wrench (spanner) and provides excellent torque when done so. Stainless Steel does not corrode, rust or stain with water as ordinary steel does, but despite the name it is not fully stain-proof, most notably under low oxygen, high salinity, or poor circulation environments. Stainless steel is used where both the properties of steel and resistance to corrosion are required. APPLICATION: 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. Ref: UTTK14575