Vlier NS55 Threaded Spring Plunger 1/4-20 1in Thread

Product Description

The VLIER NS55 is a standard threaded spring plunger designed to provide controlled, repeatable positioning force in mechanical assemblies. It uses a steel body and phenolic nose to deliver 1 pound of initial end force and 4 pounds of final end force through a 3/16 inch projection stroke. The 1/4-20 thread runs the full 1 inch body length, making it straightforward to install in pre-tapped bores. Machinists, tool-and-die technicians, and mechanical assemblers specify this plunger where consistent spring-loaded indexing or detent action is needed without a locking element.

The NS55 is suited for light-duty indexing, alignment, and positioning applications in fixtures, jigs, machine assemblies, and industrial tooling. The phenolic nose reduces marring on contact surfaces, which makes it a practical choice where metal-on-metal contact is undesirable. It is commonly installed in horizontal, vertical, or angled bores in steel, aluminum, or plastic assemblies across general manufacturing and fabrication environments.

Key Features

• 1/4-20 thread with 1 inch full-body thread length for secure installation in standard tapped holes
• 3/16 inch plunger projection provides consistent spring travel for indexing and detent applications
• 1 pound initial end force and 4 pound final end force for light-duty, repeatable positioning
• Phenolic nose minimizes surface marring on contact materials
• Steel body construction for durability in industrial tooling environments
• No locking element - allows straightforward torque-in installation and future adjustment

Compatibility

Designed as a standard 1/4-20 threaded spring plunger suitable for use in any pre-tapped bore accepting a 1/4-20 thread in mechanical fixtures, jigs, and machine assemblies.

Installation Notes

A licensed machinist or mechanical assembler typically installs this plunger using a standard hex wrench or screwdriver slot into a pre-tapped 1/4-20 bore. Ensure the bore is clean and free of debris before threading the plunger in. Do not over-torque the body, as steel threads can gall or damage softer aluminum or plastic housings. Confirm plunger projection and spring action are unobstructed after installation before returning the assembly to service.