Vlier BM4A Threaded Ball Plunger M4 X 0.7 Steel

Product Description

The VLIER BM4A is a threaded ball plunger designed for precision positioning and controlled end-force applications in mechanical assemblies. It features an M4 x 0.7 thread, a 0.098-inch (2.50 mm) steel ball diameter, and a body length of 0.354 inches. The spring-loaded steel ball delivers an initial end force of 0.90 lb and a final end force of 2.25 lb, with a maximum ball reach of 0.032 inches. This device represents the smallest and lightest class of spring-loaded plunger hardware and is installed by machinists, toolmakers, maintenance technicians, and mechanical assembly professionals working with precision fixtures and equipment.

The BM4A is suited for light-duty indexing, detenting, and positioning tasks where controlled, repeatable end force is required in a compact form factor. Typical applications include jigs, fixtures, tooling plates, and small mechanical assemblies where space constraints demand a minimal-profile threaded plunger. The purple color code provides quick visual identification during assembly and inventory management. This plunger installs in any tapped M4 x 0.7 threaded hole and requires no locking element.

Key Features

• M4 x 0.7 thread for direct installation in standard metric tapped holes
• Steel body and steel ball construction for durability in industrial environments
• Initial end force of 0.90 lb and final end force of 2.25 lb for controlled, repeatable positioning
• Maximum ball reach of 0.032 inches for precise travel control
• No locking element required, simplifying installation and adjustment
• Purple color code for fast visual identification in multi-plunger assemblies

Compatibility

Designed for use in any application requiring an M4 x 0.7 threaded ball plunger, including precision jigs, fixtures, tooling plates, and light-duty mechanical indexing assemblies.

Installation Notes

Installation requires a properly tapped M4 x 0.7 threaded hole in the mating component. Use an appropriate metric hex key or driver to seat the plunger body; do not overtighten, as this can compress the spring and alter end-force performance. Ensure the assembly is de-energized and any moving components are secured before installing or servicing plungers in active tooling or machinery.