These taps are made to match the most popular spindle sizes on lathes. Now it is easy to make wooden jigs that can be taken off and put back on the lathe.
To use the Spindle Tap, hold a face grain piece of wood in a chuck, bore a hole 1/8" less than the spindle size in it, start the tap with the tailstock live center against the end. Turn the tap with a wrench while keeping preasure by advancing the tailstock. After tapping, face off the front of the block so it will seat against the back of the lathe spindle. Then turn a recess if your lathe spindle has a non threaded area.