BaerCoil® Instruction for use (Thread Repair)

1. Drilling

Kernlochbohren im Querschnitt

Clear the damaged thread with a standard drill.
Many kits include the correct drill. To repair a spark plug thread no pre-drilling is necessary if using the special spark plug tap.
Optionally you can countersink the borehole.

2. Tapping

Gewindeschneiden im Querschnitt

Use the special BaerCoil taps for cutting the holding thread into the cleared hole.
It's recommended to use a suitable cutting oil.

3. Install the insert

Gewindeeinsatz einbauen im Querschnitt

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.

4. Tang removal

Zapfenbrechen im Querschnitt

Lift tool from tang, turn 90° and tap down sharply. Use tang break tool where supplied. For bigger sizes and spark plug use a long nose pliers to remove the tang.

Adjustment of length

Kürzung eines Drahtgewindeeinsatz mit Seitenschneider

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.

BaerCoil® Thread Repair - Video: