Vlier PRTL250P Locking Knob Handle Plunger 1/4-20

Product Description

The VLIER PRTL250P is a locking knob handle plunger designed for precision indexing, positioning, and clamping applications in industrial and mechanical assemblies. It features a 1/4-20 thread and a Delrin knob, offering a secure, hand-operable interface for repeated engagement and release cycles. The locking element holds the plunger retracted until the operator releases it, reducing unintended extension during machine setup or fixture adjustment. With an initial end force of 0.12 pounds and a final end force of 0.36 pounds, this plunger delivers controlled, repeatable spring pressure suited to light-duty locating tasks. Installation is handled by maintenance technicians and machine builders working in fabrication and fixture environments.

This plunger is suited for use in jigs, fixtures, machine tools, and production equipment where a hand-retractable, locking-style plunger is required. The 1/4-20 thread makes it compatible with standard tapped holes in aluminum, steel, and engineered plastic assemblies. The Delrin knob provides chemical and wear resistance in light industrial environments. It is appropriate for both OEM assembly integration and field replacement on existing tooling setups.

Key Features

• Locking plunger type holds the nose retracted until manually released
• Delrin knob provides durable, hand-friendly operation with chemical resistance
• 1/4-20 thread fits standard tapped holes in common fixture materials
• Initial end force of 0.12 pounds and final end force of 0.36 pounds for controlled spring engagement
• Maximum plunger diameter of 0.16 inches with a plunger projection of 0.13 inches
• Compact body length of 0.63 inches suits space-constrained panel and fixture installations

Compatibility

Designed as an OEM-style replacement or direct-fit component for industrial jigs, fixtures, and machine tool assemblies requiring a 1/4-20 locking knob handle plunger.

Installation Notes

Installation is performed by maintenance technicians or machine builders using standard hand tools. Thread the plunger into a prepared 1/4-20 tapped hole and tighten to the head shoulder using the hex size of 1/4 inch. Ensure the assembly or fixture is de-energized and stationary before installing or replacing plunger components. Do not exceed the rated end force range by substituting heavier springs or modifying the plunger body.