Vlier SSM55N Threaded Spring Plunger 1/4-20 Stainless Steel

Product Description

The VLIER SSM55N is a stubby threaded spring plunger designed for positioning, locating, and indexing applications where space is limited and reliable end force is required. Built with a stainless steel body and nose, this plunger threads into a tapped 1/4-20 hole and delivers an initial end force of 1 pound rising to a final end force of 3.5 pounds. The stubby profile keeps the overall body length at 0.531 inches, making it well suited for assemblies with tight clearance envelopes. A locking element is incorporated to secure the plunger position after installation and prevent loosening under vibration or cyclic loading. Machinists, tool-and-die technicians, and assembly engineers install this type of component in jigs, fixtures, and precision mechanisms.

The SSM55N is intended for high end force applications where available installation depth is restricted. The 0.119-inch maximum plunger diameter and 0.078-inch projection keep the footprint minimal while still providing consistent spring-loaded detent or positioning force. Common install scenarios include fixture plates, alignment tooling, machine tool components, and any assembly where a standard-length plunger would interfere with adjacent features or thin stock material. The stainless steel construction makes it appropriate for environments where corrosion resistance is a factor.

Key Features

• Stubby body length of 0.531 inches fits restricted installation spaces
• 1/4-20 thread for direct installation into standard tapped holes
• Stainless steel body and nose for corrosion resistance
• Initial end force of 1 pound and final end force of 3.5 pounds
• Locking element prevents back-out under vibration or cyclic loads
• Maximum plunger diameter of 0.119 inches with 0.078-inch projection

Compatibility

Designed for use in jigs, fixtures, and precision assemblies requiring a 1/4-20 threaded spring plunger with a stubby profile. Suited for high end force and restricted-space applications as specified by the manufacturer.

Installation Notes

Installation requires a properly tapped 1/4-20 hole at the correct depth to accommodate the full thread length of 0.531 inches. Use an appropriate hex key or spanner tool as required by the plunger head style, and engage the locking element fully to prevent loosening during service. De-energize or lock out any machinery before installing or removing spring plungers in active fixtures or automated equipment. Verify that the plunger projection and travel clearance are confirmed in the assembly before final torque to avoid binding.