I’ll confirm this:
It is crucial with titanium to keep it cool. Titanium does not transmit heat well, so the heat of the cut stays local. Metals expand when heated, so if it gets hot enough, titanium will swell and grab your cutting tool in a death grip. Do not power through! Take a break, get a cup of coffee, have lunch, or wipe the sweat off your face. When the frame is back to room temperature, slowly start the process again. Repeat as needed. I have seen T47 BB taps broken off in a new titanium frame, don’t let it happen to you! Lubrication is crucial.
Try RELTON Rapid Tap PASTE:
Or Anchorlube:
Both are available from MSC, or any good industrial supply. Rapid Tap is best, but is not water soluble. It is an effort to remove post-machining. Anchorlube comes off with detergent and hot water.
Canola oil also works very well, and is available at your local grocery store. Also a pain to clean.
I’ve also found that if a cutting tool has been used in steel, it never cuts titanium as well as before you cut steel. If you do both steel and ti, keep two cutters on hand, one for steel, one for ti. When a cutter is too dull for ti, it will still do a good job on steel.