Vlier NM55 Threaded Spring Plunger 1/4-20 Steel

Product Description

The VLIER NM55 is a stubby-style threaded spring plunger designed for precise, repeatable positioning and light-duty detent applications in industrial assemblies and mechanical fixtures. It features a 1/4-20 thread with a 0.531-inch thread length, a maximum plunger diameter of 0.119 inches, and a projection of 0.078 inches. The steel body provides durability in demanding environments, while the Delrin nose reduces friction and protects mating surfaces. Initial end force is 1 pound, with a final end force of 3.5 pounds. Machinists, tool and die makers, and mechanical assemblers install this type of plunger where controlled indexing or light retention is required.

The NM55 suits applications in jigs, fixtures, tooling plates, and light mechanical assemblies where a compact, non-locking spring plunger is needed. Its stubby profile makes it well suited for shallow-threaded bores or space-constrained assemblies. The 1/4-20 thread is a common size found across a wide range of industrial and OEM machine components, making this plunger a practical fit for many standard threaded housings.

Key Features

• Stubby plunger length type for use in shallow or space-constrained threaded bores
• 1/4-20 thread size with 0.531-inch thread length for secure installation
• Steel body construction for strength and wear resistance
• Delrin nose minimizes friction and protects contact surfaces
• 1 pound initial end force and 3.5 pounds final end force for light detent and positioning duty
• No locking element - installs and adjusts without thread-locking features

Compatibility

Designed as a standard OEM-style threaded spring plunger for use in 1/4-20 threaded housings in jigs, fixtures, and mechanical assemblies requiring light-duty detent or positioning function.

Installation Notes

Installation is performed by threading the NM55 into a properly tapped 1/4-20 blind or through hole using an appropriate hex key or spanner tool. Ensure the bore is clean and free of chips or debris before installation. Torque to the assembly specification defined by the fixture designer or OEM documentation. No special certifications are typically required for plunger installation, but follow applicable shop safety procedures when working with spring-loaded components.