Vlier SPR250 Locking Pull Ring Plunger 1/4-20

Product Description

The VLIER SPR250 is a stainless steel locking pull ring plunger designed for precise indexing, positioning, and locking applications in mechanical assemblies. It features a 1/4-20 thread with a thread length of 0.8 inches and a plunger diameter of 0.155 inches. The pull ring mechanism allows the plunger to be retracted and locked in the retracted position, freeing both hands during assembly or adjustment. End force ranges from 1 pound initial to 2.5 pounds final, making it suitable for light-duty positive-stop and detent applications. This type of component is typically installed by machinists, assemblers, and maintenance technicians working on fixtures, jigs, panels, and equipment enclosures.

The SPR250 fits into threaded bores on machine frames, fixture plates, enclosure panels, and similar structures where a compact, repeatable positioning element is required. The stainless steel construction makes it appropriate for environments where corrosion resistance is a factor, including washdown areas, food-adjacent equipment, and outdoor or humid industrial settings. The locking pull ring design is especially useful in applications where the plunger must stay retracted during part loading or changeovers.

Key Features

• Locking pull ring retracts and holds the plunger clear for hands-free operation
• Stainless steel construction provides corrosion resistance in demanding environments
• 1/4-20 thread for compatibility with standard threaded bores
• End force range of 1 pound initial to 2.5 pounds final for controlled detent engagement
• Compact body length of 1.14 inches suits space-constrained assemblies
• Plunger projection of 0.25 inches delivers consistent indexing depth

Compatibility

Designed as a direct-fit replacement or new-installation locking pull ring plunger for applications using a standard 1/4-20 threaded bore. Consult assembly drawings to confirm bore depth and clearance requirements before installation.

Installation Notes

Installation is performed by machinists or maintenance technicians using standard hand tools. Thread the SPR250 into a clean, properly tapped 1/4-20 bore and torque to the value specified in your assembly documentation. Ensure the mating bore depth accommodates the full thread length of 0.8 inches without bottoming out. Verify that the plunger travel and ring operation are unobstructed after installation before returning the assembly to service.