At AboutMechanics, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What are Spring Plungers?

Shannon Kietzman
Shannon Kietzman

Spring plungers, also known as spring loaded devices (SLDs), are devices that enclose a spring within a threaded capsule. Tool engineers often place spring plungers in their tools in order to save on time and labor, since they guarantee positive and controlled spring tension when they are used in dies, fixtures, assemblies, and jigs. They also provide accurate spring end force, which helps push through a ball or rounded nose within a tool or piece of equipment. This makes it possible for a tool or piece of equipment to perform more efficiently.

Installing springs in devices can be difficult, because they easily spring out of shape. Spring plungers, on the other hand, make this job much easier, because the spring is encapsulated safely inside. These devices are best installed with the help of a screwdriver, a hex key wrench, or a spring/ball plunger wrench.


Although spring plungers are easier to install than bare springs, it is still important to be careful when installing them. The body of a plunger is hollow and, therefore, is not strong enough to withstand a great deal of pressure when being installed. They also do not have the same head size as a bolt or a screw. Nevertheless, they are long lasting because side forces are applied to the assembly once in place.

Some spring plungers have two spring pressures. It is easy to tell the difference between these and standard versions, as the standard variety have a white nose and the duel spring pressure variety have a black nose. Some varieties also have a silver nose, indicating that they maintain light pressure.

Nylon nosed spring plungers are also available. These are used when working with softer materials, such as brass or aluminum. They have a higher strength than other spring plungers, providing top-of-the-line wear resistance and minimal deformation.

Metric spring plungers offer accuracy, uniformity, and dependability. These not only assure perfect alignment at any extension, but also feature a body made of steel and black oxide, and hardened case noses.

Discussion Comments


Could you provide a specific example when a spring plunger could be used? I'm having a hard time visualizing when or how you would use one.

Post your comments
Forgot password?
    • Worker