Tapping CFC Discovery

Tapping CFC seemed to work well.  A couple days ago, I noticed it sometimes did not.  After experiments, it appears that because CFC is not as hard as steel, if you use a handtap wrench to complete tapping a hole, you end up not keeping the tap perfectly perpendicular.  This creates slop in the hole producing an oversized hole.

Two possible solutions:

1. Tap the entire depth of the hole with the tap in the drill press chuck. Downside: lots more work.  You must sure your pilot hole is deeper than the tap depth or you may damage the threads.

2. Tap only a dozen or so threads on the drill press.  Then use those threads to start a stainless steel screw.  Turn it all the way to depth.  Downside: make sure your pilot hole is deeper than the tap depth or risk damaging threads.

Either way, I need to put a marker (adhesive tape, perhaps) wrapped around the required depth on the tap.

 

UPDATE: One of you told me about a tool that I tried to invent but did not realize was an already standard tool: a tap follower.  I ordered a Brown & Sharpe 599-792-30 Adjustable Spring Tensioned Tap Guide from Amazon.