Thread tap and the drill material: HSS (High-speed Steel). Check that thread and pitch of the tap and the bolt match. To repair a spark plug thread no Pre-drilling is necessary if using the special Spark Plug Tap.
15PC M12 x 1.25 Thread Repair Tool 15pcs Helicoil Wire Insert Kit
15pc Thread Repair Set M12 x 1.5 x 16.3mm with Drill Tap & Break Pin Tool
15pc Thread Repair Kit M12 x 1.25 x 16.3mm Drill Tap Break Pin Tool
