Threaded Insert 3/8-16 10pk

The ALLSTAR PERFORMANCE Threaded Insert 3/8-16 10-pack is an essential fastening solution for engine builders, custom fabricators, and performance mechanics working on aluminum cylinder heads, intake manifolds, and lightweight engine blocks. This product is designed to repair damaged threads and reinforce marginal thread engagement in soft aluminum alloys, ensuring reliable bolt clamping force in high-vibration and high-temperature environments.

Each helical insert features a 3/8-16 specification, the industry standard for valve cover bolts, intake mounting, alternator brackets, and water pump housings on small-block and big-block applications. The helical coil design distributes load across multiple thread engagements, dramatically increasing pullout strength compared to bare aluminum or stripped threads. Installation requires drilling the damaged hole to the appropriate size and using the included installation tool to seat the insert flush or slightly proud of the surface.

This 10-pack is ideal for machine shops, engine builders, and serious DIY enthusiasts performing head work, block modifications, or custom fabrication on street and race applications. With the ability to create a permanent, reusable threaded pocket that accepts standard 3/8-16 fasteners, these inserts provide a reliable solution for maintaining the integrity of engine components.