Jergens 30704 Threaded Spring Plunger 1/4-20 Steel Lock

Product Description

The JERGENS 30704 is a short-body threaded spring plunger designed to provide controlled, repeatable positioning force in jigs, fixtures, and tooling assemblies. The plunger threads into a standard 1/4-20 tapped hole with a 5/8-inch thread length and delivers an initial end force of 0.3 pounds, rising to a final end force of 3.5 pounds at full compression. The 0.119-inch diameter plunger nose is machined from Delrin for smooth, low-friction contact, while the body is constructed from steel for durability in production environments. A locking element is integrated into the body to secure the plunger position after adjustment, preventing rotation or back-out during operation. Machinists, toolmakers, and fixture builders typically specify this component.

This spring plunger is suited for light-duty indexing, detent, and positioning applications in machine tool fixtures, assembly jigs, and workholding devices. The short body profile is appropriate for installations where axial space is limited. With a 3/16-inch plunger projection and a black finish, the 30704 fits standard tapped-hole patterns commonly found in fixture plates and modular tooling systems. It is sold individually.

Key Features

• 1/4-20 thread size with 5/8-inch thread length for standard tapped-hole installation
• Short plunger body length of 5/8 inch for space-constrained fixture applications
• 0.119-inch diameter Delrin nose provides smooth, low-wear contact with workpiece or detent surface
• Integrated locking element locks plunger adjustment position and resists back-out
• 3/16-inch plunger projection with 0.3-pound initial force and 3.5-pound final end force
• Steel body with black finish for corrosion resistance and clean appearance in tooling environments

Compatibility

Designed as an OEM-style replacement or new-installation component for standard 1/4-20 tapped-hole fixture plates, modular tooling systems, and jig assemblies requiring a short-body spring plunger with locking element.

Installation Notes

Installation is performed by toolmakers or machinists using a standard hex wrench or spanner tool to thread the plunger into a clean, properly tapped 1/4-20 hole. Ensure the receiving hole is tapped to full depth and free of chips before installation. Disengage any spring-loaded clamping or indexing mechanisms before servicing or replacing the plunger. Do not overtighten, as this can damage the locking element or deform the Delrin nose.