Vlier BL54 Threaded Ball Plunger 1/4-20 0.125 in Ball

Product Description

The VLIER BL54 is a threaded ball plunger designed for controlled end-force applications requiring the smallest and lightest spring-loaded hardware available. It features a 1/4-20 thread size, a 0.125-inch steel ball diameter, and a body length of 0.531 inches. The spring mechanism delivers an initial end force of 2 pounds and a final end force of 4 pounds, with a maximum ball reach of 0.035 inches. Both the body and ball are constructed from steel for durability in light industrial and mechanical assemblies. This part is installed by machine builders, toolmakers, and maintenance technicians working with positioning, detent, and indexing mechanisms.

The BL54 is suited for applications where precise, repeatable end force is needed in a compact form factor. It threads directly into tapped holes and is commonly used in fixtures, jigs, tooling plates, and mechanical assemblies where space constraints demand the smallest available spring-loaded plunger. Its controlled force range makes it appropriate for light detent and positioning tasks in both production and maintenance environments.

Key Features

• 1/4-20 thread size for standard tapped-hole installation
• 0.125-inch steel ball diameter with 0.035-inch maximum ball reach
• Initial end force of 2 pounds, final end force of 4 pounds for controlled positioning
• Steel body and steel ball construction for mechanical durability
• Compact 0.531-inch body length - designed as the smallest and lightest spring-loaded device in its class
• Color code: Purple for quick field identification

Compatibility

Designed as an OEM-style threaded ball plunger for use in fixtures, jigs, tooling plates, and mechanical assemblies requiring a 1/4-20 tapped hole and controlled spring end force.

Installation Notes

Installation is performed by toolmakers, machinists, or maintenance technicians using standard hand tools. Thread the BL54 into a properly tapped 1/4-20 hole, ensuring the assembly is de-energized or depressurized before service where applicable. Avoid over-torquing the body, which can damage the spring mechanism or distort the thread engagement. Confirm ball reach clearance in the mating component before final installation.