Vlier M57 Threaded Spring Plunger 5/16-18 Steel Stubby

Product Description

The VLIER M57 is a stubby threaded spring plunger designed for high end-force applications in restricted spaces. Built with a steel body and steel nose, it threads into a tapped hole using a standard 5/16-18 thread. The plunger body and thread length are both 0.562 inches, keeping the overall installed footprint compact. Maximum plunger diameter is 0.135 inches, with a projection of 0.084 inches. Initial end force is 1.25 pounds and final end force is 4 pounds, making it well suited for indexing, positioning, and light detent work where consistent spring force and minimal installed height are required. Machinists, toolmakers, and mechanical assemblers install this type of component.

The M57 is intended for use in fixtures, jigs, machine tool components, and precision assemblies where clearance is tight and a full-length plunger body would not fit. The stubby profile allows installation in shallow boss depths or thin plate applications. The high final end force of 4 pounds relative to the small thread diameter makes it effective in demanding positioning applications where a standard-length plunger is not practical.

Key Features

• Stubby plunger length type for restricted-space installations
• 5/16-18 thread for direct installation into a standard tapped hole
• 0.562-inch thread and body length for minimal installed height
• 1.25-pound initial end force and 4-pound final end force
• Steel body and steel nose for durability in industrial environments
• No locking element - installs and adjusts without thread-locking features

Compatibility

Designed as a direct-thread replacement or new-installation spring plunger for fixtures, jigs, and mechanical assemblies requiring a 5/16-18 tapped hole and a stubby plunger profile in high end-force, restricted-space applications.

Installation Notes

Install using a hex key or spanner wrench appropriate for the drive style of the plunger body into a clean, properly tapped 5/16-18 hole. De-energize or lock out any machinery before installing or servicing spring plungers in active assemblies. Avoid over-torquing, which can deform the plunger body or damage the mating thread. Verify that the plunger projection and end-force values are compatible with the detent or positioning load requirements of the assembly before installation.