Heli-Coil has the most effective and universally accepted method of thread repair. Heli-Coil inserts quickly and permanently restores stripped, worn or damaged threads to their original size and condition. Inserts work in any part of material; aluminum, magnesium, cast iron, bronze, etc. The use of light weight materials in fuel efficient cars means more thread damage..there is a Heli-Coil insert to repair virtually every application. Restore parts that otherwise would have to be scrapped.Metric Fine Thread Repair Kit - M12x1.5 x 18.0mm Tap Part No. - 4976-12Installation Tool Part No. - 4973-12Tool Type - 3Insert Package Part No. - R3745-12Drill Size - 31/64" (Drill bit not included.)6 Inserts Per Kit