Jim Thompson wrote in
:

You can't beat PTFE lubricants - slick50 or Finish line grease from a
bicycle shop.

Good idea! When I went out to get a larger bit, I bought a vanadium
tap :-)
...Jim Thompson

If you are doing through holes, what you really want is a "gun" tap.
These push the chips out in front of the tap, so you don't have to do the
"forward 3/4 turn, back up 1/4 turn" routine to bust off the chips. They
just corkscrew out ahead of the tap.

A combination of:

1) lube

2) a guide block

3) a high quality gun tap

and you will be amazed at how easy it is to tap holes.

Doug White