Time Sert thread repair kits are approved by leading automotive manufactures. Time-Sert easily repairs stripped threads in cylinder head bolts, spark plug holes and oil drain pans as well. Many thread repair kits are available for your threaded bushing application in metric and american sizes. Time-Sert is the very best in thread repair! Time Sert 4010 thread repair kits are made in the United States. The M10x1.0 spark plug repair kit p/n 4010 tooling is more suited for holes that are 3 or 4 inches in depth. Inserts not included order separately.