Using small taps freehand is guaranteed to break them. I now use a
device called a "tapdisk" and never break taps....hardly ever (don't
want to jinx myself).
I found the instructions for making the tapdisk here:
"TAP DISK
Difficult to believe that I have not posted a tip about my Tap Disk.
Every shop should have one , and use it, to prevent small tap
breakage. I have not broken a tap within the past 10 years while
using my Tap Disk and I constantly use tap sizes 0 through 6. Take a
few minutes to make one, try it and I am sure you will opt for this
taping method whenever possible.
THE DISK
Turn an Aluminum disk, 1 1/8" OD, knurl it, center drill .144" and
part it off .325" thick. Drill NO. 43 from the OD to the ID and tap 4-
40. Install a 4-40, hex head bolt, .750" long.
TO USE
Insert the tap in the Tap Disk to it's mid point. Tighten the bolt
with a 1/4" wrench. Drill the hole to be taped in the Drill Press,
Mill or Lathe. Remove the drill, fill the hole with WD-40, or your
favorite taping fluid and grip the upper half of the tap in the
chuck, just loose enough to turn freely. Lower the spindle/tap to the
work. Use your thumb and forefinger to tap the hole. The photo below
shows the Tap Disk ready to use.
Bob Shores
Ruskin FLA"
--- In 7x12minilathe@..., Victoria Welch <wrlabs@...>
wrote:
Just to share the fun.
Got my laser edge / center finder holder all turned and bored out
and
started drilling and tapping (4-40) for the set screw / power
switch
holes. Went along nicely up until the final one (9th) where the
tap
broke.
Nothing gets it out :-(. And of course it is one of the lower
(critical) ones :-).
I tried the 4-40 tap out of my little kit from the auto parts place
and
it promply turned itself into a corkscrew :-). Broke too, but it
was
soft enough not to shatter and I was able to get it out with vice
grips.
Sigh. I suppose that this isn't a real big deal since this is
a "proof
of concept" thing and I can rotate the holder 45 degrees and put in
a
new set.
Lessons learned: When wrists get tired from doing the tapping -
take a
break rather than switch hands and cheap taps are a total waste of
time
and money (now I know what a cheap tap is :-).
Only a minor setback as I now have the holder itself worked out and
can
easily enough duplicate it.
Not a bad day!
Take care, Vikki.
--
Victoria Welch, WV9K/7
"Windows, another fine product from the folks who brought you
edlin." --
Unknown
