Vlier SPRT250P Knob Handle Spring Plunger 1/4-20

Product Description

The VLIER SPRT250P is a knob handle spring plunger designed for indexing, positioning, and light-duty holding applications in mechanical assemblies. This non-locking plunger features a Delrin knob for easy manual actuation without tools. It installs into a 1/4-20 threaded bore and delivers an initial end force of 0.12 pounds, ramping up to a final end force of 0.36 pounds at full plunger depression. The body length measures 0.63 inches, with a plunger projection of 0.13 inches and a maximum plunger diameter of 0.16 inches. Machinists, tool and die makers, and mechanical assembly technicians are the typical installers for this type of hardware.

The SPRT250P is suited for use in fixtures, jigs, tooling plates, and light mechanical assemblies where repeatable manual positioning is required. The non-locking design allows the plunger to retract freely under load, making it appropriate for detent or locate-and-release functions. It is installed in standard 1/4-20 threaded housings in both ferrous and non-ferrous components across industrial and manufacturing environments.

Key Features

• Non-locking plunger type allows free retraction under applied load
• Delrin knob handle enables tool-free manual actuation
• Initial end force of 0.12 pounds, final end force of 0.36 pounds for light-duty detent applications
• Compact body length of 0.63 inches suits tight-clearance installations
• Plunger projection of 0.13 inches with a maximum plunger diameter of 0.16 inches
• Locking element included for secure thread engagement in the bore

Compatibility

Designed as an OEM-style spring plunger for standard 1/4-20 threaded bores in mechanical fixtures, jigs, tooling plates, and general industrial assemblies.

Installation Notes

Installation is performed by machinists or mechanical assembly technicians using standard hand tools. Ensure the threaded bore is clean and properly tapped to 1/4-20 before installation. Torque the plunger body into the housing until the locking element engages securely. Do not over-tighten, as this may damage the Delrin knob or distort the plunger mechanism.