Vlier BM8A Threaded Ball Plunger M8 X 1.25 Steel

Product Description

The VLIER BM8A is a threaded ball plunger designed for controlled end-force applications where precise, repeatable positioning or detent action is required. The body threads into an M8 x 1.25 tapped hole and houses a spring-loaded steel ball that engages a mating detent or surface. The steel body measures 0.63 inches in length, and the ball diameter is 0.196 inches with a maximum ball reach of 0.059 inches. Initial end force is 3.37 pounds and final end force is 6.75 pounds, making this one of the smallest and lightest spring-loaded plunger devices available for light-duty positioning tasks. Licensed machinists, tool-and-die makers, and mechanical assembly technicians are the typical installers.

This plunger is suited for use in jigs, fixtures, machine tools, and precision assemblies where a low-profile, threaded spring-loaded device is needed to index, locate, or retain a component with controlled force. The M8 x 1.25 thread size is common in metric tooling and light industrial equipment. Its compact body length and minimal ball reach make it appropriate for applications with tight space constraints. The purple color code aids in quick identification during assembly and maintenance.

Key Features

• M8 x 1.25 thread for direct installation into a standard metric tapped hole
• Steel body and steel ball construction for durability in industrial environments
• 3.37-pound initial end force and 6.75-pound final end force for controlled, predictable detent action
• Maximum ball reach of 0.059 inches suits tight-clearance assemblies
• Compact 0.63-inch body length - one of the smallest spring-loaded plunger designs available
• Purple color code for fast visual identification on the shop floor

Compatibility

Designed for installation in any component or fixture with a standard M8 x 1.25 threaded hole requiring a spring-loaded ball plunger for indexing, detenting, or light retention duty.

Installation Notes

Installation is performed by threading the BM8A into a pre-tapped M8 x 1.25 hole using an appropriate hex key or spanner; torque to the fixture or equipment manufacturer's specification. Ensure the mating detent or surface is aligned with the ball centerline before final seating. De-energize or lock out any powered equipment before servicing assemblies that contain this plunger. Do not exceed the rated final end force by over-compressing the ball, as this may damage the internal spring.