Threaded Insert 3/8-16 10pk

The ALLSTAR PERFORMANCE Threaded Insert 3/8-16 10-pack (SKU ALL 19467) is a set of steel threaded inserts designed to repair and reinforce threads in stripped or damaged bolt holes. These inserts restore the integrity of worn fastener holes, allowing you to reuse the original hole size without drilling and tapping to a larger diameter. This 10-pack provides multiple repair solutions for engine blocks, aluminum castings, cylinder heads, and other critical engine components where thread failure would compromise structural integrity or fluid sealing.

Each insert is manufactured from steel and features a 3/8-16 thread specification, matching standard fastener sizing used across automotive, marine, and industrial applications. The 3/8-inch diameter with 16 threads per inch provides robust load-bearing capacity when installed in the correct helicoil or threaded insert hole. Installation requires a precision-drilled pilot hole and the appropriate insert tool, but once seated, these inserts deliver permanent thread repair that often exceeds the strength of the original material. The compact 10-piece set weighs just 0.24 lbs, making it practical for shop inventory or field repair kits.

Mechanics, engine builders, and restoration specialists rely on threaded inserts when aluminum heads strip during repeated assembly cycles, when cast iron blocks suffer corrosion damage, or when threads are accidentally damaged during machine work. Unlike drilling and retapping to the next larger size—which reduces fastener options and clearance—inserts restore the original bolt size. This is especially critical in engine bay applications where space is tight and OEM fastener specs must be maintained. The 3/8-16 size is among the most common thread repairs in small-block and mid-size engine work.