Threaded Inserts | Compression Limiters

Overview

Compression limiters have only a couple features in common. Though they fall within the camp of inserts, they are unthreaded bushings that can be as simple as a short metal barrel. Sometimes it can have a flanged head, a knurled outer diameter, an undercut, or some combination of any of these features. The name describes the purpose of these parts; compression limiters keep plastic from becoming overloaded when a joint is too tight, which can cause the plastic to degrade. The metal compression limiter both provides a positive stop to indicate when the joint is “fully” fastened, and sustains any additional load caused by over tightening.

Installation

These parts can adopt any of the installation methods associated with threaded inserts but can also forego any of the features for a simple, pressure-fit, hollow cylinder. This is possible because without threads, the compression limiter isn’t concerned with torque-out or pull-out, and only counteracts the stress induced in the plastic. However, one of the more permanent installation methods may be useful for applications in which the compression limiter serves as an electrical contact point, or if more precise positioning is desired. In short, the name is a sort of catch-all to describe a wide variety of custom solutions to application-specific joint loading problems.