MIDWEST FASTENER CORP 31505 Nylon Insert Lock Nut 5/8"-11 Steel Grade 5 Zinc

5/8"-11 Grade 5 Lock Nut

This nylon-insert lock nut provides a reusable fastening solution for 5/8"-11 threads. The steel Grade 5 construction delivers reliable tensile strength for structural and mechanical joints. Zinc plating adds a layer of corrosion resistance for general-purpose use. It suits maintenance crews, fabricators and DIY builders securing heavy-duty assemblies.

Nylon insert resists vibration loosening

The captive nylon collar creates prevailing torque that maintains clamp load when equipment vibrates or cycles thermally. Unlike free-spinning nuts, it stays tight without chemical thread-lockers or secondary locking washers. The insert remains effective through multiple removal and reinstallation cycles. This behaviour reduces re-torque intervals on critical connections.

Zinc finish and unified thread fit

The zinc coating protects the steel substrate during storage and in typical indoor or sheltered outdoor environments. Unified 5/8"-11 threads ensure compatibility with standard bolts, studs and threaded rod of the same specification. No specialised tools are required beyond a common wrench or socket. The nut installs quickly in the field or on the bench.