Vlier PH54B Threaded Spring Plunger 1/4-20 Steel

Product Description

The VLIER PH54B is a standard threaded spring plunger designed for indexing, positioning, and light-duty detent applications in mechanical assemblies. It features a 1/4-20 thread with a 3/4 inch thread length and a steel body and nose. The spring delivers 2 pounds of initial end force and 9 pounds of final end force, with a middle end force of 5.5 pounds, giving installers a predictable, progressive engagement feel. The plunger diameter ranges from 0.117 to 0.118 inches with a 1/8 inch projection. This component is typically installed by machinists, toolmakers, and maintenance technicians working on jigs, fixtures, tooling plates, and precision mechanical assemblies.

The PH54B suits standard threaded applications where a compact, non-locking spring plunger is needed. It installs into a tapped 1/4-20 hole and delivers repeatable spring-loaded positioning without a locking element. Common use cases include fixture alignment, slide detents, and panel positioning in both production and maintenance environments. The 3/4 inch body length fits flush or near-flush in typical plate stock thicknesses used in tooling and fixture fabrication.

Key Features

• 1/4-20 thread size with 3/4 inch thread length for direct installation into standard tapped holes
• Steel body and steel nose for durability in industrial and tooling environments
• Progressive spring force: 2 pounds initial, 5.5 pounds middle, 9 pounds final end force
• 1/8 inch plunger projection for low-profile detent engagement
• No locking element - installs and adjusts with standard hex tooling
• Minimum plunger diameter 0.117 inches, maximum 0.118 inches for consistent fit

Compatibility

Designed as an OEM-style replacement or new-installation spring plunger for standard 1/4-20 tapped holes in mechanical fixtures, tooling plates, jigs, and precision assemblies requiring a non-locking threaded spring plunger.

Installation Notes

Installation is performed by machinists or maintenance technicians using a hex key sized to the 0.079 inch hex drive. The receiving hole must be tapped to 1/4-20 before installation. Ensure the assembly is de-energized and stationary before servicing any spring plunger in a live fixture or automated system. Do not overtighten, as this may compress the spring beyond its designed travel and reduce detent performance.