Broken tap

[rabjr]

Ok guys whats best way to tackle a broken tap. I broke off a piece of a 6-40 tap and not sure how to get it out.

 

Depends on how hard it is stuck and where it is.

Sometimes you can use a center punch and back the tap out by gently tapping on the edges of the flutes, but the flutes a tiney on a 6/48.

Sometimes you have to shatter the broken section and take it out in parts.

In the machine shop we used to EDM them out if all else failed.

This is not one of my favorite things to do. Ranks right up there with root canals!

Good luck.

:front:

 

[hornbuilder]

swamp rat:}

no matter what you end up trying, most important thing to remember is your safety glasses. those little pieces can do a lot of damage in eyes.. :m2c:

 

[WRussell]

This would be in a blind hole, of course? If it's a through hole, smack it from both sides until it loosens or shatters.

There are tools made for the purpose, that extend prongs (itty bitty in this case) down into the flutes of the tap, which you can use to get a grip and back it out.

Improvising is usually just as good.

Find a couple of wires/old drills that you can stick down into the flutes, then grab them as close as possible with a small vice or vice grip pliers, and see if that gives you enough grip.

Work the tap in both directions to try and get it loose.

Some light oil can help

If that fails, try shattering it. Sometimes that will break off everything that isn't stuck and leave you with a stuck piece and no way to get hold of it. You'll find it when you try to clean up the hole with a drill.

Drill alongside, hammer the piece out sideways, clean up the mess with a bigger drill, silver solder a plug in and start over.

 

[Killitgrillit]

Howdy swamprat
Don't sweat it, you can buy broken tap removers or listen to the above mentioned advice(they know what there talking about) I work with taps and heli-coil's everyday and deal with this all the time. just remeber before that tap broke off it made threads down to where it was, so with a little coaxing and the right tools it will back right out. I use to use two scribes I would but one down a flute and then use vice gripes and turn it out. If your using a 4 flute tap you can get them 180deg out with a 3 flute it's close enough. if nothing else listen to the above mentioned advice and get a nail set punch and try to break it up by hitting it and breaking it up in to smaller pieces
good luck :m2c:

 

[Darkhorse]

Before you do anything drastic take one of those scribes and pick at the pieces of broken tap, if there are any. Often a small piece will stick in the threads and jam the broken tap in place. Picking at these pieces will sometimes dislodge them and also loosen up the broken tap.
A good strong blast of compressed air (with the hole covered by a rag for safety) will sometimes blow some of these pieces out also.
If you can manage to loosen the tap, which also means backing it away from the chip it was cutting when it broke, then you stand a good chance of backing it out without busting it up and boogering up the hole any worse.
If you do get it out be sure and run another tap in, with oil, and reversing the tap often to break the chip. With a small tap I'll tap about 1/3 hole diameter, then back it, then tap another 1/3 and so on.
Slow but faster than breaking little taps.

 

[TANSTAAFL]

Howdy swamprat
Don't sweat it, you can buy broken tap removers or listen to the above mentioned advice(they know what there talking about) I work with taps and heli-coil's everyday and deal with this all the time. just remeber before that tap broke off it made threads down to where it was, so with a little coaxing and the right tools it will back right out. I use to use two scribes I would but one down a flute and then use vice gripes and turn it out. If your using a 4 flute tap you can get them 180deg out with a 3 flute it's close enough. if nothing else listen to the above mentioned advice and get a nail set punch and try to break it up by hitting it and breaking it up in to smaller pieces
good luck :m2c:

Good advice. On such a small tap I have used appropriate size music wire to get down into the flutes. If not a blind hole push the wires through, one can then get a double purchase from either side on the tough wires and apply some serious torque. It worked, sometimes.

Above all, know that you have a lot of company, most all of us have heard the dreaded "SNICK" sound. Said sound can lend new meaning to the term, "primeval scream," even when done in total silence.

 

I tried all that stuff to no avail when I busted a tap in my jaeger lock plate and ended up taking it to a machine shop and they tig welded a nut onto the microscopic nub sticking through and turned it out that way. Cost me twenty bucks I tried to turn that sucker just a tad too much before backing it out a bit and "Snap"! That was a sickening sound.

 

[Herb]

I think I have cut broken small taps out with a Dremel tool and a carbide dental burr. Your dentist will throw away dull burrs that will still cut steel like butter. The ones I use are cylindrical, maybe .040 or .050 in size, look like a little drill. They will cut out a broken tap.

 

[Birddog6]

My dentists must use cheap bits. I got a handfull of them from them & none of them are worth the trouble of chucking up. The diamonds ones clog to easily (which is why they use them flushing with water all the time they are using them) and the rougher ones will not cut steel . They will cut brass or german silver if you run them at real slow speeds but overheat easily. None of the ones I got would even make a mark on a tap.
Next time I go I will tell them I want the good sh//, not the cheap stuff ? :crackup: I am sure I have paid for a many of them ! :shake:

:results:

 

[rabjr]

Thanks guys, I was able to carefully back it out using a small punch as it was only in by 2 threads.

 

[flashpanner]

Whew! sweated that one!! :thumbsup: Did we learn something here? (yea, do what ever it takes to not bust one of them bugers off!!)
Tink!!!! NOT a good sound to hear when tapping holes!!

 

[scott k]

Not all of the bits that dentists use are carbide. The ones that are carbide should have 1 or 2 lines around the shaft to id it as carbide.
I cut ball joints out of upper arms in cars with them and those ball joints are hard.
What kind of tap you are using determines how hard it's going to come out. Most hand taps are carbon steel and if you smack them hard with something hard(like a center punch)
they usually will shatter. Good luck getting out the pieces in a blind hole :curse: Bin there done that.
Machine taps that are HSS are real fun when they break off. If you hit them they just go in deeper. You have to try to back them out if you can.
The one machine shop I worked in had a edm thing to take out broken taps. I never did use it but it seamed to make a real big hole and a piece of scrap all at the same time :crackup:
Lehigh...

 

[madstone]

I use my drill press to tap holes as soon as they are drilled and usually I can merely drill out the offending broken tap w/o resetting their position. Lots and lots of cutting/tapping oil and letting the drill press chuch keep the tap straight helps, too. Air to blow out chips and going really slow seems to work. Usually one only learns this after breaking lots of taps and swearing, though.

 

[captgary]

I always check the drill bit with a mic to be sure it is the correct one, Always use a good tapping compound (not just anything that is handy) And work the tap slowly, back it out every so often and remove chips. Same thing with wood screws make sure pilot hole is the right size, then lube the screw the first time in. I came to the conclusion a long time ago that the best way to deal with broken taps and screws is not to break them.

 

[robinghewitt]

the best way to deal with broken taps and screws is not to break them.

Unfortunately, there's only one way to learn how not to break them. Experience is that thing you get just after you needed it most :thumbsup:

 

[captgary]

Unfortunately, there's only one way to learn how not to break them. Experience is that thing you get just after you needed it most

Boy thats for sure!!!!!!!

 

[Zonie]

Before some of our novice builders get the idea that power tapping with a drill press will prevent broken taps may I give my opinion?

Using a drill press to tap holes is a very specialized process. Many of the machines which industry uses to do this have special sensors to measure torque and they will stop and back out the taps before the taps break.
In other words, don't chuck up your tap, turn on your drill press and move the chuck down to start the tap. It will break the tap faster than you can swear.

Yes, I do use my drill press to start the tap but this is all done by hand.
Using the chuck to hold the tap, I apply Thread Cutting Oil to the tap and the hole. This is special oil with sulfur added to prevent tap breakage. (Regular motor oil does not work well).

Lowering the chuck I then turn the chuck/tap by hand to start it into the piece part.
I do not make over 3 complete turns before I back the tap completely out of the hole.
This will produce a good, perpinduclar starting thread for the tap to follow while hand tapping.

Remove the tap from the chuck and start it back into the hole by hand taking special care to prevent cross threading.
After the tap is screwed in as far as I can using finger pressure, I install a tap handle and proceed to finish the threads using hand pressure only.
If the tap, for any reason becomes very hard to turn, back it out about 1 turn and apply more Thread Cutting Oil.
It is a very good idea to stop tapping after making each turn. Back the tap out about 1/2 turn, then proceed to thread another turn.
Continue this until the tap seems to "run freely".

Doing this can reduce the chanch of breaking the tap to almost nothing.

Just remember, we are building hand made rifles where speed is not important.
IMO, anything that will speed up the process is also something that will get you in trouble even faster.

 

[Roy]

I have with success broken several taps :grin: from 8's down to 4's. Seems like I had a real knack for it. When I can not back it out (leaving that ity-bity hard as glass bit in the bottom of the hole) I heat the piece to cherry and place it in used up charcoal from the grill. The coal lets the piece cool of slowly and removes the temper(hardness) from the tap. Then drill it out and try, try again.