Vlier PH54AN Threaded Spring Plunger 1/4-28 Steel

Product Description

The VLIER PH54AN is a threaded spring plunger designed for indexing, positioning, and light-duty detent applications in mechanical assemblies. Machined with a steel body and steel nose, this plunger threads into a tapped hole to provide repeatable spring-loaded pressure against a mating surface or detent recess. It features a locking element to secure it in place once adjusted, preventing loosening from vibration or normal service loads. The 1/4-28 thread and 1-inch thread length suit a wide range of standard tapped fixtures. Initial end force is 3 pounds, middle end force is 8 pounds, and final end force is 13 pounds, giving installers a predictable force progression across plunger travel.

This plunger is used in machine tool fixtures, jigs, assembly tooling, indexing mechanisms, and general industrial equipment where a spring-loaded locating or holding force is required. The standard plunger length type and 3/16-inch projection make it well suited for applications requiring a compact, low-profile engagement. Maintenance technicians and machine builders install this type of component during tooling setup, fixture assembly, or equipment overhaul. Both light manufacturing and precision mechanical assembly environments are common install contexts.

Key Features

• 1/4-28 unified fine thread for secure, precise installation in standard tapped holes
• Locking element prevents rotation and back-out under vibration or load
• Steel body and steel nose for durability in industrial environments
• 3-pound initial end force and 13-pound final end force for predictable detent action
• 3/16-inch plunger projection provides compact engagement depth
• Hex drive (0.079 inches across flats) allows installation with a standard hex key

Compatibility

Designed as an OEM-style replacement or direct-install spring plunger for mechanical fixtures and assemblies using a 1/4-28 tapped hole with a 1-inch minimum thread engagement depth.

Installation Notes

Installation is typically performed by machine builders, toolmakers, or maintenance technicians using a hex key sized to the 0.079-inch hex drive. Thread the plunger into a clean, properly tapped 1/4-28 hole and tighten until the locking element engages to resist back-out. Verify plunger travel and projection clearance before final assembly. Do not overtighten, as doing so may damage the locking element or restrict plunger movement.