Vlier SSPH57 Threaded Spring Plunger 5/16-18 Stainless Steel

Product Description

The VLIER SSPH57 is a threaded spring plunger designed to provide controlled, repeatable positioning force in mechanical assemblies. The body and nose are both constructed from stainless steel, offering corrosion resistance in demanding environments. It features a 5/16-18 thread with a 1 inch thread length and a standard plunger projection of 3/16 inch. Initial end force is 1.5 pounds, middle end force is 3.0 pounds, and final end force is 4.5 pounds, giving installers a predictable force curve across the full plunger stroke. This part is installed by machinists, toolmakers, and mechanical assemblers in precision fixturing and positioning applications.

The SSPH57 is suited for use in jigs, fixtures, tooling plates, and mechanical assemblies where a spring-loaded detent or positioning element is required. Its compact plunger diameter of 0.133 to 0.135 inches and standard body length of 1 inch make it appropriate for space-constrained installations. The stainless steel construction makes it a practical choice for environments exposed to moisture, cleaning agents, or light chemical contact. It carries no locking element, relying solely on spring force to maintain plunger position.

Key Features

• 5/16-18 thread for straightforward installation into standard tapped holes
• 1 inch thread length and 1 inch body length in a compact, standard-length profile
• Stainless steel body and nose for corrosion resistance
• 3/16 inch plunger projection with a defined force range: 1.5 lb initial, 3.0 lb middle, 4.5 lb final end force
• No locking element - spring-only retention for smooth, repeatable actuation
• Minimum plunger diameter 0.133 inches, maximum 0.135 inches for consistent fit

Compatibility

Designed as a standard threaded spring plunger for mechanical assemblies, jigs, and fixtures requiring a 5/16-18 threaded detent or positioning element with a standard 1 inch body length.

Installation Notes

Installation is performed by threading the SSPH57 into a properly tapped 5/16-18 hole using a hex key sized for the 0.093 inch hex drive. Ensure the mating hole is clean and free of debris before threading the plunger in. Do not overtighten, as excessive torque can deform the body or restrict plunger movement. De-energize or immobilize any moving machine components before servicing spring plungers in active assemblies.