BaerCoil® Instruction for use (Thread Repair of Spark Plug)

1. Drilling and Tapping

To repair a spark plug thread no pre-drilling is necessary if using the special spark plug tap.

2. Install the insert

Place insert on installing tool and position the adjustable ring so that the insert tang is centred in the tang slot. Wind insert in with light downward pressure until 1/4 to 1/2 turn below the surface.

3. Tang removal

For spark plug use a long nose pliers to remove the tang.

Adjustment of length

If necessary, you can shorten BaerCoil wire thread inserts by side cutting pliers to any needed length.

Due to the narrow and exact tolerances the new thread normally is stronger than the original one.


  • Thread reinforcement: For material with low shear strenght eg. aluminum-alloys and magnesium alloys.
    Used in machine-building, electrical, automotive, medical and aerospace industries.
  • Thread Repair of damaged or worn-out threads.
  • Recovery of rejected items.