MIDWEST FASTENER CORP 76305 5/16" Black Phosphate Steel Pushnut Bolt Retainers 40PK hardware

5/16″ Pushnut Bolt Retainers

This pack contains 40 black phosphate steel pushnuts sized for 5/16 inch bolts. Each nut uses inward-facing flanges that grip the shaft when pressed or lightly tapped into position. The phosphate finish provides a degree of corrosion resistance for general hardware use. Removal requires cutting the retainer off the bolt.

Suited for permanent or semi-permanent fastening

Mechanics and fabricators who need a quick, threadless retainer on 5/16 inch rods or bolts will find these convenient. They are not intended for applications that demand repeated adjustment, high clamping force, or a reusable fastener. Builders requiring a threaded nut or a locking mechanism that can be undone with hand tools should select a different hardware type.

Behaviour under sustained load

The flanged teeth maintain their grip as long as the shaft diameter stays within the nominal 5/16 inch tolerance and the assembly is not subjected to severe vibration that could walk the nut loose. Because the retainer is designed for one-way installation, it does not back off like a threaded nut, but the holding force is limited to the spring tension of the flanges. In high-stress or safety-critical joints a positive locking nut or a welded solution is more appropriate.