How to add an ejection tang to a Morse taper for a metal lathe

[NortonDommi]

Most people cut the tang off if they are going to use a tanged arbor in a lathe tailstock. Closed barrel tailstocks have a stop inside that will release the arbor when it is wound in all the way. Tangs interfere with seating in these designs. Open barrel tailstocks you hit the end of the arbor with a punch.
The ejection tang is more for use in a pedestal drill for removal from the quill.
The easiest solution is buy the correct arbor for the job. If you have a mill with the same taper by an open end threaded arbor to suit the draw-bar of choice and some buttonhead screws in the appropriate thread, this lets you fit a screw for use in the tailstock. Most pedestal drills have hollow quills so you can use a draw-bar on these as well but a tang is easier.