Check that the thread and of the tap and the bolt match for Ideal for restoring damaged threads , stripped internal threads and creates a for internal thread in soft metals Place insert on installation tool and position the adjustable so that the insert for tang is centered in the for tang slot Wind the insert in with a light downward pressure until a half turn below the surface Never work against the thread direction as the for tang could break Use the special taps for cutting the holding thread into the cleared hole ( recommended to use a suitable cutting oil Clear the damaged threads with a standard drill, Manufacturer: Watreketal