Mike - you are not giving us enough info. How many parts? What dia is the thread? It looks like a small thread.
First - since the part is metric I would stay with a standard metric fine thread.
Second - for the inside thread I would make an undercut and than cut from the inside out - or - I would try to find a metric standard fine tap. Buy two and grind one of them flat bottom going. Start with the first one and finish with the second one to the undercut. Don't forget to put a nice chamfer in front.
For the plug - you can cut as close as possible with a tool bit having a small tip.
You take a regular tool bit like a 5/16 x 5/16 and on the left side grind a 30 deg angle almost to the front. Than tilt another 30 deg. and grind to a small tip ( you can make a tip just slightly larger than the depth of your thread). You will than end up with a 60 deg. tip. Grind your clearance by hand.
Set compound to 29 1/2 deg and align the left ( first ground) angle with the face of your spindle or 90 deg to the thread. Cut to an undercut. The chamfer on the internal thread will help you - or - buy a die, cut with one (the chamfered side) and follow up with the other side of the die that is almost a sharp full thread. Check the die and make sure it has one side with a chamfered start and the other side starts with a thread that has a very short chamfer.
If you can not find one - grind one side. Juergenwt  |