Vlier NNS55A Threaded Spring Plunger 1/4-28 Steel

Product Description

The VLIER NNS55A is a threaded spring plunger designed for precise positioning, indexing, and light-duty latching applications in mechanical assemblies. The body is machined from steel with a Delrin nose, providing corrosion resistance at the contact point while maintaining structural rigidity in the threaded shank. The 1/4-28 thread allows installation into tapped holes with a standard fine-thread tap. Initial end force is 1 pound, with a final end force of 4 pounds, making it suitable for applications requiring a light, repeatable detent feel. Licensed trade professionals and mechanical assemblers install this plunger using standard hand tools.

The NNS55A is used in machine tool fixtures, jigs, tooling plates, and general industrial assemblies where a spring-loaded ball or nose plunger is needed to hold, locate, or index a moving component. The fine 1/4-28 thread provides good thread engagement in thin panels or close-tolerance assemblies. With a standard plunger length type and a body length of 1 inch, this part fits into compact assemblies where space is limited. It is installed by machinists, tool and die makers, and mechanical maintenance technicians.

Key Features

• 1/4-28 fine thread for precise installation in tapped holes
• Steel body for durability and structural rigidity
• Delrin nose material reduces wear and friction at the contact point
• 1 pound initial end force and 4 pound final end force for light detent applications
• Standard plunger length type with 3/16 inch projection
• No locking element - installs and adjusts with a standard hex wrench or screwdriver slot

Compatibility

Designed as an OEM-style replacement or direct-install spring plunger for mechanical assemblies requiring a 1/4-28 threaded spring plunger with a 1 inch thread length.

Installation Notes

Installation requires a properly tapped 1/4-28 hole in the receiving component. De-energize or lock out any moving machinery before installing or adjusting spring plungers in active assemblies. A thread-locking compound may be used if vibration is a concern, though this part includes no integral locking element. Consult applicable machine tool or fixture standards for torque and engagement requirements.