Midwest Fastener 5/8 in.-18 Castle Hex Nut

The Midwest Fastener 5/8 in.-18 Castle Hex Nut provides secure, dependable fastening in heavy-duty mechanical and automotive applications. Engineered with precision slots designed to accommodate a cotter pin, this castle nut helps prevent accidental loosening caused by vibration and dynamic loads. Constructed from durable Grade A steel with a protective zinc finish, this fine-thread fastener offers excellent resistance to corrosion and wear. It is ideal for critical assemblies such as wheel hubs, steering linkages, and suspension components where positive locking is essential.