Check the listing for details. 25Pcs 5/16"-18 Nylon Insert Hex Lock Nuts, Carbon Steel Nut, White. Condition: New. Listed at 11.76 USD. Description:Material - Made of carbon steel with galvanized surface treatment, the nylon insert hex lock nuts have anti-rust and anti-corrosion properties. The material has high hardness, oxidation resistance, high-temperature resistance, durability, and is not easily deformed, and can be used for a long time.Features - There is a nylon insert in the insert locknut, which is closely combined with the bolt thread. The nylon insert locknut can produce a certain elastic deformation after the bolt is tightened, resulting in frictional resistance, which can prevent the bolt from loosening caused by vibration or other factors.Easy to Use - Nylon insert hex lock nuts are easy to use, insert the bolt into the nut, align the threads, and tighten with a wrench.