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. Spring plungers serve this function because they guarantee positive and controlled spring tension when they are used in dies, fixtures, assemblies, and jigs. Spring plungers 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. Spring plungers 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 spring plunger is hollow and, therefore, is not strong enough to withstand a great deal of pressure when being installed. Spring plungers also do not have the same head size as a bolt or a screw. Nevertheless, spring plungers 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 spring plungers and standard spring plungers, as the standard variety have a white nose and the duel spring pressure variety have a black nose. Some spring plungers also have a silver nose, indicating that they maintain light pressure.

Nylon nosed spring plungers are also available. These spring plungers are used when working with softer materials, such as brass or aluminum. Nylon nose spring plungers 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 spring plungers not only assure perfect alignment at any extension, but also feature a body made of steel and black oxide, and hardened case noses.