As George has said lots of good advice so far...

but I'll go one further than he and Jon have said about a tapping block,

build yourself a tapping fixture like this.

http://www.ggls.org/TappingFixture/

It's an afternoon project with hardware store parts.

I posted this here several years ago and got an incredible amount of
positive feedback on it, and about 5 months ago Matt Mason published this in
his "LGRR" Magizine...

Oh I'm I "buy the best" kind of guy... "Cheap tools are false economy"

--.- Dave



"Jon" wrote in message
news:bHAwk.719$Wd.490@trnddc01...

"F. George McDuffee" wrote in message
news
On Fri, 5 Sep 2008 17:09:18 -0700 (PDT), "Mr. INTJ"
wrote:

- The work I'm doing is generally smaller stuff - the kind of thing
you'd find in small electronic and electromechanical appliances. I
think this means I should be looking for a set with 2-56 to 1/4-inch
UNC threads.

- Then there's the question of coarse threads vs. fine. Seems like if
I had to choose, coarse would be the way to go, but as with std vs.
metric (above), I worry about constantly needing the one that I don't
have.
=================
Several good replies in this thread.

Depending in which corner of the electronics area you will
working, I think you will find a much smaller set of threads in
actual use.

My suggestion is to buy good, not necessarily the best, taps as
you need them, but as you buy, don't get just a single tap, but
rather several styles such as taper, plug, bottoming, gun, etc.
Also when you buy the taps get screw machine length [short] tap
and body drills. 135 degree split points tend to be
self-centering. The exotic coated taps are great for production,
but for the home shop, offer minimal benefit.

A good place to store these are plastic ammo boxes available at
most sporting goods stores and harbor freight. Remember taps are
brittle and will chip if banged together or dropped if an edge is
hit.

To save yourself considerable aggravation and broken taps get a
good tap wrench of the appropriate size, and make or buy a tap
guide block to insure that the taps start straight [#1 cause of
broken taps]. Also good are the tap holders that pilot off the
drill spindle or spring loaded tap guides.

Use a good quality tap lube when tapping. ["A little dab will do
ya" for hand tapping]

Be sure to back the tap up frequently to break the chip and avoid
binding/breakage. When the tap gets tight, back it out, [you may
need to rock it back and forth] and clean off the chips to avoid
breakage.

Above all take your time and don't force anything.

Good luck, and let the group know how you make out.



When I entered the machine shop as a full-time employee, my first tool was
a tap guide. it was an old shaft key, 1.25"square by 8 long, mild steel.

I drilled a series of holes from #10 thru 1/2"

Twenty years later, I reach for it at least once a week.