Vlier BL56N Threaded Ball Plunger 5/16-18 Steel

Product Description

The VLIER BL56N is a threaded ball plunger designed to provide controlled end force in positioning, indexing, and detent applications. It features a 5/16-18 thread, a steel body measuring 0.578 inches in length, and a steel ball with a 0.156 inch diameter and a maximum ball reach of 0.04 inches. Initial end force is 2 pounds, with a final end force of 4.25 pounds. A locking element is included to secure the plunger in position once set. This part is among the smallest and lightest spring-loaded devices in its class, making it well suited for installations where space and weight are at a premium.

The BL56N is used in mechanical assemblies where repeatable, spring-loaded ball detent action is required. Typical applications include fixture tooling, jigs, machine slides, and precision equipment where controlled positioning force must be maintained. The compact 5/16-18 threaded body allows installation into tight clearance areas. Technicians and machinists working in industrial, automation, and trade equipment environments will find this plunger appropriate for both OEM builds and field-service replacements.

Key Features

• 5/16-18 thread for standard tapped-hole installation
• Steel body and steel ball for durability in demanding environments
• Integrated locking element to hold set position
• Controlled end force: 2 pounds initial, 4.25 pounds final
• Compact 0.578 inch body length - one of the smallest and lightest spring-loaded devices available in this thread size
• Color code: Purple for quick field identification

Compatibility

Designed as a standard threaded ball plunger replacement or OEM-style component for mechanical assemblies requiring a 5/16-18 threaded detent device with controlled spring force.

Installation Notes

Installation requires a properly tapped 5/16-18 threaded hole in the receiving component. Use appropriate thread-engagement depth to ensure the locking element functions correctly. Avoid overtightening, which can damage the locking element or restrict ball travel. Ensure the assembly is de-energized and free of movement before servicing or replacing plunger components in automated or powered equipment.