Small tap advice needed

[WKevinD]

Almost every time I am trying to tap a 6/32 I break a tap, I use a #36 drill, lube the tap and go slow I reverse to clear chips when I feel pressure and continue s-l-o-w When I get about three fourths thru I snap the lil bugger.
If I have a small web I try and use a 6/32 for the front lock bolt and much more anxiety than I should have for tapping a hole.

Any recomendations on drill size, tap mfg. or technique?

Kevin

[smylee grouch]

I had a similar situation once and when I got the lock out of the stock and the rest of the tap out I finished taping the hole out side of the stock. It didn't break then. I have since started to work slower and clear the chips more often.

[bama]

Most of the time I break a tap it's because it has gotten dull. I have started paying more attention to how many holes I tap with a tap. The second I have to start. Struggling with a tap I change to a new one. I break very few taps now.

[okieboy]

 The front of the tap has a taper called the tap chamfer. this determines how many turns of the thread are required before the tap is cutting a full thread. The most common chamfer is called a plug and cuts a full thread in 3-5 turns. In a through hole you could use a taper tap (often called a starter tap) which has 7-10 turns before full thread, this spreads the cutting out considerably and reduces the torque required to cut the thread.
 In shallow blind holes, bottoming taps (1-2 turn chamfers) are often used, but they generate the highest torque values, so they have short tool life.
 So, the longest chamfer that can be used in the hole that you are tapping will give you the easiest most successful tapping and the most holes per tap.

[David Rase]

I have to agree with bama on this one, a dull tap is your worst enemy.  I too have learned (the hard way) to toss out old dull taps.
David

[Mike Brooks]

I'd like to add, they don't make taps like they used to. I inherited a bunch of taps back from one of my Grand Pa's back in the late 80's. Those things  go on for ever. New ones I'm lucky to get three holes tapped.

[WKevinD]

I guess I need to invest in a few tapered taps...any recomendations on a supplier or mfg.
For all the aggravation I get from 6-32s and #36 drills I'll just use them once for iron and twice for brass maybe that will help
Thanks,

Kevin

[Scota4570]

Clamp the part to the drill press table.  Drill.  Leave it in place.  Put a tap guide in the chuck.  Back off the return spring on the drill press quill.  Use the drill press to keep the tap running perfectly straight in the hole.  I do the same thing but with a milling machine. 

I never tap small holes free hand.  It is inviting disaster.  If the tap squeaks fall back and reassess. 

[P.W.Berkuta]

Good advise Scota4570.

To the OP and others: I have taps & dies from the 60's and they have MANY miles on them. They range in size from 0-80 to 7/8 X 14.  I have broken a few but not many 80% of my taps and dies are H.S.S. and have been use on mild to O-1 tool steels also brass and aluminum. If you are having trouble tapping and chasing threads you need to get some further education on how to tap holes and thread round stock. Practice is a good starting point as is a good tapping fluid.

[smallpatch]

I agree with Paul.
I've only broken one tap, and it was because it was forced with NO tapping lube.
Tap Magic will make them work sooooo easy.

[Dennis Glazener]

I'd like to add, they don't make taps like they used to. I inherited a bunch of taps back from one of my Grand Pa's back in the late 80's. Those things  go on for ever. New ones I'm lucky to get three holes tapped.

Is it because we don't fork out the money for high quality taps? I know I have a couple sets of tap/dies that were bought by my dad in the 50 and 60's and I still use them. But like you some of the new ones are dull after 3 or 4 uses. I know I tend to be a cheapskate and not buy the expensive American made one's I justify it but saying I will probably break them before I wear them out anyway!
Dennis

[rick/pa]

 I have been using a 50/50 mixture of ATF and kerosene for lube fluid.

[Mark Elliott]

I'd like to add, they don't make taps like they used to. I inherited a bunch of taps back from one of my Grand Pa's back in the late 80's. Those things  go on for ever. New ones I'm lucky to get three holes tapped.

Is it because we don't fork out the money for high quality taps? I know I have a couple sets of tap/dies that were bought by my dad in the 50 and 60's and I still use them. But like you some of the new ones are dull after 3 or 4 uses. I know I tend to be a cheapskate and not buy the expensive American made one's I justify it but saying I will probably break them before I wear them out anyway!
Dennis

I have been using a bunch of Greenfield taps that I got from my Grandfather for decades.   Many of them were new in the box when I got them and they are from, I believe,  the 70's, when the tobacco company he worked for shut down in Richmond.    I don't buy anything close to that expensive these days.  I just can't afford to.   

[RichardW]

If you are tapping through holes, let me suggest you try a Spiral Pointed tap. They have an angle cut on the point of the tap that will push the chips ahead of the tap and keeps them from packing in the flutes. Do not use them on a blind hole as the chips will pack in the bottom of the hole.

Starting with a properly sized hole, good lube and a sharp tap, most taps break from misalignment with the hole or putting side pressure on them. See Scota4570’s previous reply about alignment.  If you don’t have a drill press a tiny square will help or look at the tap from different angles to make sure it’s going in straight.

[Bill Raby]

   For hand tools I tend to get the best quality that you can get and not care what it costs. If I cannot afford it, I save up for it. I build rifles because I enjoy doing it. Lousy tools just take all the fun out of it. Really good tools are a joy to use. I get a bit cheaper on the power tools. I avoid junk and get the cheapest that is adequate to do the job. Figure that the motor does all the work. I agree with getting the good taps and replace them when they get worn out. I think of the time I was too cheap to spend an extra $4 on a tap and it broke. By the time I got that thing out of there I would have gladly paid an extra $50 for one that would not have broken!

[Maineshops]

Where it is not critical to have a 80% I use the next size drill and always use a tapping block. It is difficult to break a tap that is kept straight. I've tapped thousands of 8 and10/32 taps in the drill press with minimal issues. Dan

[Chris Evrard]

Clamp the part to the drill press table.  Drill.  Leave it in place.  Put a tap guide in the chuck.  Back off the return spring on the drill press quill.  Use the drill press to keep the tap running perfectly straight in the hole.  I do the same thing but with a milling machine. 

I never tap small holes free hand.  It is inviting disaster.  If the tap squeaks fall back and reassess.

Agree with the above.

I tap 300-600 holes per week. Of course an automatic tapping head is one of my main shop tools, but the idea is the same. It is absolutely necessary to keep the tap plumb with the bore of your hole. Especially with the small taps.

Use oil.

I'll diverge here on the plug taps. I use exclusively spiral point taps now for lock work (not to be confused with spiral flute taps). Spiral point taps push the chip ahead of the tap and are the hizzy when it comes to tapping through holes in thin-ish stock, just like most lock/gun work.

I buy high quality taps, Guhring, OSG, Kennametal, etc. I get hundreds of holes from a single tap including 6-40's.

Best,

Chris E.

[Goo]

Tapping oil is not the same as regular oil it makes a difference.   Some taps are designed for steel others for aluminum and othe non ferrous  metals. If you buy your taps at the hardware store those are best used for chasing out already tapped holes that need to be dressed and cleaned up.   Taps come in different designations for the depth of cut on the threads and you have to start with one that doesnt cut so deep then maybe on to the next one.  Adjustable dies are the same way back out the set screw expand the die and make the first pass then tighten and repeat. Domestic taps cost more than imports because they are worth it, they have to be tempered properly so they hold a cutting Edge but are not too brittle.   Cold taps break easier than warm ones.   

[Bob Roller]

Almost every time I am trying to tap a 6/32 I break a tap, I use a #36 drill, lube the tap and go slow I reverse to clear chips when I feel pressure and continue s-l-o-w When I get about three fourths thru I snap the lil bugger.
If I have a small web I try and use a 6/32 for the front lock bolt and much more anxiety than I should have for tapping a hole.

Any recomendations on drill size, tap mfg. or technique?

Kevin

The 6x32 is a wretched thread. IF a #6 thread is needed then use a 6x40 and a #33 drill.
Countersink the hole the depth of ONE thread on both sides and use a drop or two of threading
fluid.Fewer broken taps and a cleaner job.

Bob Roller

[Hungry Horse]

 Tapping fluid is formulated to facilitate tapping good clean threaded holes. Never dry tap a hole without it. I would steer clear of homegrown recipes, and buy whatever your local machinist uses. Broken taps cost him time, and money, so he will avoid them by using the tapping fluid that works best for him. I have used RapidTap for years, with good results.

  Hungry Horse

[Dan Fruth]

Cheap taps are junk steel. Buy the best taps you can. Always use a good lube when tapping....6-32 tap drill and % of thread engagement..........37 drill=84%; 36 drill=78%; 7/64=70%; 35 drill=69%...........for your reference a 29drill =69% thread engagement for 8-32 thread....Thought you might like to know.

[Scota4570]

"The 6x32 is a wretched thread. IF a #6 thread is needed then use a 6x40 and a #33 drill.
Countersink the hole the depth of ONE thread on both sides and use a drop or two of threading
fluid.Fewer broken taps and a cleaner job."

Why not use 6-48?  It is a standard modern gun size.  Brownells has high quality screws and taps. 

I really hate obscure size screws.