Vlier NS56 Threaded Spring Plunger 5/16-18 Steel

Product Description

The VLIER NS56 is a standard threaded spring plunger designed to provide controlled, spring-loaded positioning and indexing force in mechanical assemblies. The body is steel with a phenolic nose, offering durability in light-to-medium duty applications. The plunger installs into a 5/16-18 threaded bore with a 1 inch thread length and delivers an initial end force of 3 pounds, increasing to a final end force of 15 pounds at full compression. Plunger diameter runs 0.133 to 0.135 inches with a 3/16 inch projection. This type of component is typically installed by machinists, toolmakers, or mechanical assembly technicians during fixture and jig builds or equipment assembly.

The NS56 is suited for use in machine tools, fixtures, jigs, and industrial equipment where repeatable spring-loaded detent or positioning action is required. The 5/16-18 thread size fits standard tapped bores commonly found in aluminum, steel, and cast-iron machine components. The phenolic nose reduces scoring on mating surfaces, making it appropriate where metal-on-metal contact would cause wear or marking. No locking element is present on this plunger, so the thread engages the bore through standard thread friction alone.

Key Features

• 5/16-18 thread with 1 inch thread length for secure installation in standard tapped bores
• 3 pound initial end force rising to 15 pound final end force for positive detent action
• Phenolic nose minimizes surface marking on mating components
• Steel body construction for strength in industrial assembly applications
• 0.135 inch maximum plunger diameter with 3/16 inch projection
• No locking element - installs and adjusts using standard tooling

Compatibility

Designed as a standard OEM-style replacement or new-install threaded spring plunger for mechanical fixtures, jigs, and industrial equipment requiring a 5/16-18 threaded bore with a standard-length steel plunger body.

Installation Notes

Installation is performed by machinists or mechanical technicians using a hex wrench or spanner suited to the plunger body. Ensure the mating threaded bore is clean and free of debris before installation. Disengage or isolate any mechanical or pneumatic energy in the assembly before servicing spring plunger positions. Do not over-torque the body into the bore, as this can deform the thread and affect spring travel.