Vlier H55N Threaded Spring Plunger 1/4-20 Steel Locking

Product Description

The VLIER H55N is a threaded spring plunger designed for positioning, indexing, and light-duty detent applications in mechanical assemblies. It features a 1/4-20 thread with a 1 inch thread length and a 3/16 inch plunger projection. The steel body and steel nose provide durability in standard industrial environments. A built-in locking element secures the plunger in the threaded bore after installation, preventing loosening from vibration or repeated actuation. Initial end force is 1 pound, with a final end force of 4 pounds, making it suitable for low-to-moderate detent force requirements. Machinists, toolmakers, and mechanical assembly technicians are the primary installers.

The H55N is used in jigs, fixtures, machine tool components, and precision mechanical assemblies where repeatable part positioning or detent action is required. It threads directly into a tapped hole and applies controlled spring force through the nose to hold or index a mating component. The compact 1 inch body length allows installation in tight-clearance assemblies. This plunger suits both prototype and production applications across general manufacturing and industrial tooling environments.

Key Features

• 1/4-20 thread size with 1 inch thread length for standard tapped-hole installation
• 3/16 inch plunger projection provides controlled nose travel for detent engagement
• Steel body and steel nose construction for durability in industrial use
• Locking element secures plunger in bore and resists loosening from vibration
• 1 pound initial end force and 4 pound final end force for light-duty indexing applications
• 1/8 inch hex size allows installation and adjustment with standard hex key tooling

Compatibility

Designed as an OEM-style threaded spring plunger for installation in any mechanical assembly with a 1/4-20 tapped bore requiring standard spring plunger detent or positioning function.

Installation Notes

Installation is performed by machinists or mechanical assembly technicians using a 1/8 inch hex key. The mating bore must be tapped to 1/4-20 prior to installation. Ensure the bore is clean and free of debris before threading in the plunger. The locking element engages the bore threads as the plunger is tightened - do not over-torque, as this can deform the locking element or damage the thread.