Gibraltar 57191G Threaded Spring Plunger 3/8-16 Steel

Product Description

The GIBRALTAR 57191G is a threaded spring plunger designed for indexing, positioning, and light retention applications in mechanical assemblies. It features a 3/8-16 thread with a 1-1/8 inch thread length and a 3/16 inch plunger projection. The steel body provides durability in industrial and trade environments, while the Delrin nose reduces wear on mating surfaces. A locking element secures the plunger in place once installed, preventing loosening from vibration. With an initial end force of 2.8 pounds and a final end force of 7.2 pounds, the 57191G delivers consistent, repeatable spring force for precision fitment work.

This spring plunger is suited for machine tool fixtures, jigs, assembly tooling, and panel hardware applications where a compact, threaded retention device is needed. The standard-length plunger body fits into threaded bores in steel, aluminum, and similar materials. Machinists, tool and die technicians, and maintenance mechanics typically install this component during equipment assembly or fixture fabrication. The black finish provides basic corrosion resistance for general shop and industrial use.

Key Features

• 3/8-16 thread size with 1-1/8 inch thread length for secure installation in standard threaded bores
• 3/16 inch plunger projection provides consistent indexing or retention engagement
• Steel body construction for strength and durability in industrial environments
• Delrin nose material reduces wear and friction on mating contact surfaces
• Locking element prevents backing out under vibration or repeated cycling
• 2.8 pound initial end force and 7.2 pound final end force for precise spring load performance

Compatibility

Designed as a standard threaded spring plunger for use in threaded bores requiring a 3/8-16 thread form. Suitable for jigs, fixtures, tooling plates, and general mechanical assemblies that require a spring-loaded positioning or retention element.

Installation Notes

A licensed machinist or maintenance technician installs this plunger by threading it into a pre-tapped 3/8-16 bore using the 3/16 inch hex drive. Ensure the bore is clean and free of chips or debris before installation. The locking element should be engaged after the plunger is positioned to the correct depth to prevent movement during operation. Avoid overtightening, which can compress the spring element beyond its working range.