Pick it out with an old scriber, EDM, or make a hollow cutter and core it out

Maybe worth a try for the time it will take to make.

1/4 " dia. silver steel , drill 1/4" deep with a drill core size of tap, reduce dia. to core size of hole, junior hacksaw

to form three castellations on the end , gently try to drive it into spaces of the tap.

Try to turn it out.

Domestic sewing needles and pins are fairly tough. If they can get a point into a flute then 2 or 3 through drill holes in scrap with minimal stick-out?

pgk

I did this recently. Managed to drift it round using a scriber and a little toffee hammer. Just little glancing blows so it starts to spin.

I've taken broken 2, 2.5 and 3 mm taps out with carbide three flute centre cutting end mills without damage to the partially cut threads.

Machine was a Bridgeport with the end mills held in R8 collets. Pucker factor high!

Annoyingly I've mislaid the cutter details. Thing brand began with N—-.

Clive

Were you tapping into brass or aluminium ? You can dissolve a broken tap by putting the whole thing in an Alum solution.

Edited By Brian John on 15/09/2021 04:59:36

You may get lucky with trying to move it by other means but short of spark errosion it's definitely best to make a hollow cutter – 7 Ba clear inner and about a 1mm wall section. Cut the teeth with a file for left hand direction. Harden but dont temper. Slow's the word with constant swarf removal from the teeth. Slow process but it works (believe me!!). Once out, clean hole with next size drill and turn cast iron plug to suit, loctite in place and carry on as before.

Good luck for an efficient recovery

Tug