How to use a small drill tap wrench?

Should be a small dimple in the back of the tap or in the wrench handle. Put a center point in a drill press lower it into the dimple while the tap is where you want it and lock the Z axis of the drill press.
Start tapping,
Might need to unlock and lower it, but once you start cutting the tap should just keep going straight.

A ha!  A drill press!  Thank you.  I have one, but it's probably too big for model RR jobs....

What are you tapping?  At my job we put the tap in a cordless drill, wax it for lubrication and run it in slowly. 

Some consider it a waste of money. If you plan on doing very much prewar or postwar work. Invest in a Dremel drill press or the Dremel table that accepts the Dremel hand held power unit. The cost is minimal for the quality work that can be done. IMHO

Thanks to all.  I need to tap a new [bigger] hole in a truck bolster, if that helps.  I WILL look into the Dremel stuff.  And B 4 that,i may try the suggestion of using a cordless drill, at low speed....with wax.

Tapping very small holes is actually easy if you have the correct tools.  Try a good eight dollar tap (probably by now they are $15 each for 0-80).  It should say "Greenfield" or at least "made in USA" and have only two flutes.  It needs to be a taper tap, and you need, need, need cutting fluid.  Try that, and you will be an expert in no time.

 

But small taps get dull and break.  I get no more than about 80 holes with a really good tap before it crystallizes and breaks - usually in the hole.

The recommendation that Boilermaker1 gave should be tried first. Chuck your part in a vise, align the hole with the tap, and bolt the vise to the drill press table. The size of the drill press is irrelevant. Another option is to get a hand tapper that will make tapping a lot easier. Freehand power tapping is not recommended; always insure a tap is started and driven completely perpendicular to the hole to avoid bad threads or worse, a broken tap.

 

Larry

I do all my tapping by hand, using a small bar type tap wrench, similar to this one offered by Micro Mark. I was taught to back the tap about 1/4-1/2 turn frequently to break the chips away and clear the grooves.

 

I find that the tap wrenches with a "T" shaped handle with a chuck on the end do not work well with small taps. The taps do not lock in properly. Maybe I do not have the proper sized tool.

I use this:

 

 

Micro Mark #83146

I use a pin vise. It's easier to spin a single rod than something with a T bar on it. The T bar really is a dumb device if you want to keep the tap aligned.

 

quote:

 The T bar really is a dumb device if you want to keep the tap aligned.

 

Funny, I don't seem to have a problem. Maybe it's because I rarely go smaller than a 2-64 or a 2-56 tap.

 

If you are just beginning to get into tapping, I would suggest that you avoid complications and tap by hand. I never had a need to go with power options.

 

IMO you need to feel what resistance you are encountering and judge when to back out to remove chips from the hole. Most broken taps are due to the hole becoming clogged or to an incorrect pilot hole.

 

I also never had a problem with the T-wrench. Just make sure you have drilled the correct number pilot hole (check the charts), and be sure to start off perpendicular to the surface with a light touch. Drill presses are a great way to drill the pilot hole, but not to hold the tap. Keep life simple.

 

Jim

Here are some commonly used screw/pilot combinations in modeling:

 

00-90  drill #63

0-80    drill #55

1-72    drill #53

2-56    drill #50

3-48    drill #46

4-40    drill #43

6-32    drill #35

 

Jim

For the smaller taps I use little screwdriver-like tap holders.  Like Jim, I find that smaller holes are easily done by hand.  It is the larger holes that I find need alignment tools, and I do those on an 11" lathe with collets and stuff.

 

My experience sort of qualifies me to comment - my average locomotive frame has a minimum of thirty tapped holes.  The big articulateds with eight axles run well over a hundred tapped holes each.  The average boiler can have as many as 30, and I generally attach appurtenances with steel 0-80s.  There are over 35 such models around here, including 9 large articulated and compound locomotives.

Thx for all the info.....B 4 trying any of the suggestions, I decided to bring it to a local HO club meeting, to show it to some of the 'experts' there.....More later; after Tuesday nite.

 

I use a rather oversize "t-wrench" that my was my grandfather's which is just a chuck off a modest drill press adapted to this use all the way down to 2/56.  I had a smaller one, but the collet worn badly.  For smaller sizes, and depending on the material & thickness, a pin vise with a large collet works fine.

 

One thing that the OP did not relate was just what material he was tapping and its thickness.  Different materials can be quite different in tapping.  It's not always brass, steel or die cast, but one can also drill & tap resin, and most plastics with perfectly fine results.