04-05-2015, 07:45 PM
(04-05-2015, 10:33 AM)Mayhem Wrote: I cannot see myself buying straight flute taps again. Power tapping is awesome
Same here. Excepting the occasional special tap (screw thread insert, Acme, etc.), I will use only spiral point (through holes) or spiral flute (blind holes) for tapping, even when tapping by hand. Those are always seem to be good HSS or HSS-E (5% cobalt), and are just plain stronger than high carbon steel hand taps.
A few days ago I had to tap a blind 5/16-18 in steel, but had no spiral flute. I used a spiral point tap in the lathe, but did only start it under power and finish with a tap wrench.
The 5/16-18UNC H3 spiral flute tap is on it's way now. I'll be adding a few more too, but not much over 5/8" taps. Beyond that I can single point thread them.