-=> Jay Emrie said to Mike Ross
 -=> about "CHUCKS" on 01-11-03  10:10.....

 JE> My 1/4" drill chuck goes at least down to a #60 (.040") - I
 JE> can't locate my set of bits that go to #80. That's far
 JE> smaller than a 1/16" bit. I have used a #80 in the past
 JE> without any special chuck.

#80 = 0.0135" which is a bit less than 1/64".

I have no doubt that a precision 1/4" chuck, in good condition,
will take drills that small.

To hold such a small bit, the part of the jaw that actually grips
the bit must be very narrow. For the same chuck to hold a 1/4"
bit doing heavy work, the pressure on that part is enormous and
it will suffer some degree of flattening.

Usually the jaws are made with a comparatively large flat on that
part so they can grip the larger drills adequately. As a result,
the average chuck on a 1/4" jobbers drill usually won't hold
anything smaller than 1/16", and not even that if it's worn.

From Greg Mayman, in beautiful Adelaide, South Australia

... If a string has one end, it has another.
___ Blue Wave/386 v2.30

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