With a distorted internal thread and keys on the outside, these inserts create a strong hold on both fasteners and surrounding material. Together, the distorted thread and keys create a mechanical lock that resists pull-out from vibration or temperature changes and is stronger than inserts that require threadlocker. Use them to create completely new threads, add strong threads in soft metal, or replace existing threads that are damaged or need to be resized. They're often seen in molds, tools and dies, and suspension systems in vehicles.

Made of a solid piece of metal, these inserts are also stronger than helical inserts, which are made of coiled wire. A dry-film lubricant makes it easy to install them and to screw fasteners into them. All are made to tight tolerances with strictly controlled materials; many inch sizes also meet military or aerospace standards for dimensions and material.

To install, you'll need a tap to create the threads in your material, and an installation tool and a hammer to drive the keys into the material.

When choosing between stainless steel and cadmium-plated steel, consider strength and price. Both materials withstand wet environments. Stainless steel inserts are economical, but not as strong as steel. Use cadmium-plated steel inserts in applications where additional strength is necessary, such as in engine blocks. Steel inserts are stronger than stainless steel inserts, but are more expensive.

Inserts with thick walls are the most commonly used; they’re stronger than thin-wall inserts and are used in larger holes.

For technical drawings and 3-D models, click on a part number.