The plastic or nylon insert in the stainless steel nylock nut is placed at the end of the fastener. The inner diameter or the ID of this nylon insert slightly smaller than the major or bigger diameter of the screw.Over time, the insert of the stainless steel nylock wing nuts deforms elastically. This is because the threads of the screw, does not have threads in turn cut into it. The nylon insert locks the 3/8 stainless steel nyloc nuts by applying friction against the screw under the applied radial compressive force.
One of the limitations faced by the stainless steel nylock wing nuts is that they cannot be used at elevated temperatures and with some chemicals. Using these nuts at elevated temperatures can deform the nylon insert which is thermoplastic in nature.
Indian standard for nylock nut retain their locking ability up to 250 °F or 121 °C.Manifold Pipe Solution Inc. is one of the leading suppliers and nylock nut manufacturer in India.