Steel Lock Hexagonal Nut With Nylon Insert DIN985 is a self-locking hexagonal nut with a nylon insert inside. Made of steel, it has high strength and can withstand large tension and compression. The nylon insert provides additional locking force, making it stable in high vibration environments. Meigesi Fastener can provide nuts of different specifications and materials, such as 304 stainless steel, carbon steel, etc.