Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Yeah, you don't want to do 300 holes by hand. 

For machine tapping, you don't want to use a hand tap because you should break the chips by reversing the tap.  What you want is a HSS gun tap which will push the chips down through the hole.  Straight in and straight out.  You probably want to set the speed of your drill press to it's lowest setting and use plenty of cutting fluid.  The taps are not that expensive, MCM stocks one at $7.

If you had a blind hole, you can get taps that pull the chip upwards and out.  They look sorta like a cork screw.  Not necessary in your case.

For people unfamiliar with a tapping head, this video shows how they work.



For the record, I don't own a tapping head.  I just use my mill which has reverse and slower speeds.