The strongest key-locking inserts we offer, these inserts are made to stringent military specifications. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. Inserts may be mildly magnetic. They’re comparable to Keensert® inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.

Inserts with a thin wall are often used in small holes or near the edge of a workpiece.

Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.

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

These inserts are made to stringent military specifications. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. Inserts may be mildly magnetic. They’re comparable to Keensert® inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.

Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.

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

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 thin walls are best for small holes or near the edge of a workpiece. They’re also commonly used in electronics applications that require small fasteners. 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.

These assortments include various sizes of key-locking inserts with thick and thin walls, and an installation tool. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or convert threads in soft metals such as aluminum. They’re comparable to Keensert® inserts.

18-8 stainless steel inserts are more corrosion resistant than black-phosphate steel. They may be mildly magnetic.

Black-phosphate steel inserts are mildly corrosion resistant.

Thin-wall inserts are often used in small holes or near the edge of a workpiece.

Choose assortments with thick-wall inserts for greater strength than thin-wall inserts, or to fill a large hole.

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

Inserts come with a through-hole tap and installation tool. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw.

Assortments include various sizes of helical inserts and a tap, a drill bit, and an installation tool for each thread size. Also known as Heli-Coil inserts, the inserts have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw.