Jergens 30305 Threaded Spring Plunger 5/16-18 Steel

Product Description

The JERGENS 30305 is a short-body threaded spring plunger designed for positioning, indexing, and light-duty detent applications in mechanical assemblies. The body is steel with a black finish, and the nose is made from Delrin for low-friction contact with mating surfaces. The 5/16-18 thread provides a secure, repeatable installation in tapped holes, and the built-in locking element prevents the plunger from backing out under vibration. Initial end force is 0.50 pounds, and final end force is 10.00 pounds, giving the plunger a firm, positive feel at full engagement.

This plunger is used in tooling fixtures, jigs, machine components, and industrial assemblies where a spring-loaded detent or locating point is needed. The short body configuration suits tight-clearance installations where a standard or heavy-duty body would not fit. It is typically installed by machinists, tool and die makers, and mechanical assembly technicians during fixture builds or equipment maintenance.

Key Features

• 5/16-18 thread size with 5/8-inch thread length for standard tapped-hole installation
• Locking element prevents plunger from loosening under vibration or repeated cycling
• Delrin nose reduces friction and wear on mating contact surfaces
• Steel body with black finish for corrosion resistance in light industrial environments
• 0.50-pound initial force to 10.00-pound final force range for positive detent engagement
• Short body length suits tight-clearance and space-restricted installations

Compatibility

Designed as a direct-fit threaded spring plunger for any tapped hole with a 5/16-18 thread, compatible with standard fixture plates, jig bodies, and machine components requiring a short-body spring plunger configuration.

Installation Notes

Installation requires a properly tapped 5/16-18 through-hole or blind hole with sufficient depth for the 5/8-inch thread length. Power down or de-energize any associated equipment before servicing assemblies containing this plunger. Use the appropriate hex key or tool on the locking element to secure the plunger at the correct engagement depth. Avoid over-tightening, which can distort the locking element and affect spring performance.