1) Applying a sideways force (not just a torque) to
the tap. Often
by using a ppoor tap wrench
I suspect a tap extractor would work for case (1), but
the sort of
person to have a tap extractor is also the sort of person to use the
right tap wrench and apply an even torque to it.
Yes...but everyone makes mistakes occasionally. (Which is why tap
extractors find a market, I daresay.)
I've broken tools like drill bits and taps now and then. Most of them
are things like my grip slipping or some such - where I knew what to do
and was trying to do it, but Something Went Wrong - but there have been
a few cases that were pure brain fade....
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