Vlier NM56N Threaded Spring Plunger 5/16-18 Steel

Product Description

The VLIER NM56N is a stubby threaded spring plunger designed to provide controlled, repeatable positioning force in mechanical assemblies. It features a 5/16-18 thread with a body length of 0.562 inches and a maximum plunger diameter of 0.135 inches. The plunger delivers an initial end force of 3.75 pounds and a final end force of 15.5 pounds, making it suitable for applications that require a defined resistance to movement. A locking element is included to secure the plunger in the threaded bore after installation. The steel body provides durability in industrial and mechanical environments. Machinists, tooling technicians, and mechanical assembly professionals are the primary installers of this component.

This spring plunger is used in fixturing, jigs, tooling plates, and precision mechanical assemblies where a spring-loaded detent or positioning stop is required. The stubby form factor is suited for installations with limited axial space. The Delrin nose reduces wear on mating surfaces and minimizes marring on workpieces or indexed components. Applications span light industrial machinery, assembly fixtures, and general mechanical positioning systems where consistent spring force and compact size are priorities.

Key Features

• 5/16-18 thread with 0.562 inch thread length for standard tapped hole installation
• Stubby plunger length of 0.562 inches suits confined axial spaces
• Plunger projection of 0.084 inches provides a low-profile detent engagement
• Initial end force of 3.75 pounds and final end force of 15.5 pounds for defined positioning resistance
• Delrin nose reduces surface marring on indexed or mating components
• Steel body with locking element for secure, tamper-resistant installation

Compatibility

Designed as an OEM-style replacement or direct-install spring plunger for mechanical assemblies, fixtures, and tooling that accept a standard 5/16-18 threaded spring plunger with a stubby body profile.

Installation Notes

Installation requires a properly tapped 5/16-18 threaded bore of sufficient depth to accept the full 0.562 inch body length. The locking element should be engaged after the plunger is threaded to the correct depth to prevent backing out under vibration or repeated cycling. Use appropriate thread engagement practices and verify plunger projection after installation before putting the assembly into service. Power down or de-energize any equipment before servicing assemblies that contain spring plungers.