Centre 1/4" hex brass stock and extend 6mm from the jaws. Face end, centre-drill and drill with ascending drills to Ø2.6mm x 15mm deep.
Use high spindle speed, back drill out several times to clear. Tap M3 x .5mm to full depth. Finish turn shoulder to Ø6mm x 1mm long and part off with 1.6mm blade at 2.5mm from faced end.