Thread jig is mounted directly in the lathe, you clamp the cutter head on the drive shaft, and the workpiece itself in the fixture holder, and with this setup you turn the workpiece around, while it moves towards the engine block, which then makes a precise thread.
It can make 1.5mm and 2.5mm threads. Max thread length 50mm.
The thread cutter head itself has an M33x3.5 thread.
