On 12/29/2011 11:44, Bob La Londe wrote:
What is the best tapping oil/fluid for aluminum? The oil I am using now
is a general purpose cutting machining oil. I tap a lot of 10/32 holes
and it would be nice (for convenience) if I could get some more use of
of my taps. I can tap about 40-50 (+/-) holes through 1/2" 6061-T6 bar
stock and the clutch starts to slip on my tapping head. If I try to get
any more out of it, I'll break the tap within another 2-5 holes.
Breaking a tap off in an otherwise finished work piece really sucks.

When I replace taps I back off the clutch and then tap a hole. I'll
tighten it a little at a time, and when the tap goes all the way through
with out slipping just barely I'll give it about 1/32 of a turn more.
That seems to work pretty good with this head.

The other thing I wonder about. I have been buying spiral flute taps.
Not because I need to tap blind holes, but because gun taps seem to be
hard to find labeled clearly and correctly. I know when I buy a spiral
flute tap its intended for machine tapping. If I can find clearly marked
gun taps for machine tapping would they be stronger than the spiral
flute taps?





Use roll form taps. Heavy oil. Way better tap life. Use correct size
drill for roll forming. 1 or 2 thousandths makes a BIIIIIIG difference
in tap life.



--
Steve Walker
(remove brain when replying)