Help Removing Broken Tap

[MBG]

I did a dumb thing. I was tapping a bling hole and I used a high torque drill-driver. When the tap hit bottom....SNAP! Is there any way to remove the tap? As exprcted it is very hard - my drill bits wont even put a dent in it.

Mike

[Thom2]

you'll need 6 things

1. a good chisel
2. a good hammer
3. a case of beer
4. a lot of patience
5. the vulgarity handbook
6. lots of determination

When you're not beating or cussing, you should be drinking and reading, if you're not drinking and reading, you should be beating and cussing.

HTH

Thom

P.S. as sarcastic as that sounded, it was pretty much the truth. The only way I know to get them out is to break them up little by little with a hammer and chisel. Maybe somebody else has a better way tho'.

[Thom2]

ya know, I never even thought to ask, was this in wood or metal????

I just assumed metal

[LCHIEN]

you'll need 6 things

1. a good chisel
2. a good hammer
3. a case of beer
4. a lot of patience
5. the vulgarity handbook
6. lots of determination

When you're not beating or cussing, you should be drinking and reading, if you're not drinking and reading, you should be beating and cussing.

HTH

Thom

P.S. as sarcastic as that sounded, it was pretty much the truth. The only way I know to get them out is to break them up little by little with a hammer and chisel. Maybe somebody else has a better way tho'.

I agree with Thom about the 6 items required. And oh yes, once you get tired of Thom's procedure, then you toss out your workpiece and start over. At least, that's how I did it last time. (is that more sarcastic than Thom's answer?)

Sheesh, driving a tap with a power driver. Even if it didn't hit bottom you probably would've broke that sucker off.

[Jim Boyd]

In another life we used tap extractors. This is the first hit with google. Pretty good pics and description. http://www.newmantools.com/walton/extrtap.htm#sets

If these don't work then it was the hammer and chisel

[ted van halen]

I broke a drill (3/32) in a screw yesterday drilling for an easy-out. This was in the process of replacing roller bushings on a planer I borrowed & have used <1hr. Me thinks I am the benefactor of a bum tool, or perhaps a bum friend. My ethics will not allow me to return it broken. To no avail, I first employed the available components of the 6 step method above. At any rate I ended up using a dremel w/a cut-off wheel to cut straight down thru the bit. This wrecked the mounting boss on the planer but there is still adequate support for the bushing retainer. Fortunately I got the remaining screw out & there is plenty of thread in the hole to grab when I re-assemble later today. I am considering building up the boss w/ 2-part epoxy & then re-drilling & tapping. I'm no help, but I do hate it for you.


Ted

[WayneJ]

I broke off an exhaust manifold stud in cylinder head. Next I broke off the eazy out. Then I called an old racing buddy of mine.He heated up the broken parts with a cutting torch as hot as he could get it. He then shut off the flame and stood back and hit it with pure oxygen, The stud and easy out blew itself out of the hole. When it cooled retapted the hole and was good to go. Thom was right about the beer, we had a few after that.
Wayne

Don't know if anyone knows Pappy Huff from the old midget racing days, He is the one who did it.

[MBG]

Jim thanks for the constructive info - McMaster has one for about $10!


...and LCHIEN - they also sell adapters for tapping threads with a hand drill.

Sheesh, driving a tap with a power driver. Even if it didn't hit bottom you probably would've broke that sucker off.

[Thom2]

...and LCHIEN - they also sell adapters for tapping threads with a hand drill.

I think Lorings point is that you can't 'feel' a tap when using a power drive, I never use a power tool to drive a tap, never have, never will. Whenever I'm tapping steel with full threads, I turn the tap no more than 1/2-1 turn, then back off at least 1/4-1/2 turn. I know this is probably overkill and many will tell me I don't have to do it this way, but this is how my machinist grandfather taught me and how I've always done it. The 1/2 turn insures a small bite, backing out a 1/4 turn insures the threads are cleaned up and the chips ejected from the tap and also allows the tap to 'relax'. I've never broken a tap doing things this way and I'm not about to take my chances at changing now. I know doggone well that if I break a tap off, it'll be the day that I'm out of #3 on that list

[maxparot]

I broke a drill (3/32) in a screw yesterday drilling for an easy-out. This was in the process of replacing roller bushings on a planer I borrowed & have used <1hr. Me thinks I am the benefactor of a bum tool, or perhaps a bum friend. My ethics will not allow me to return it broken. To no avail, I first employed the available components of the 6 step method above. At any rate I ended up using a dremel w/a cut-off wheel to cut straight down thru the bit. This wrecked the mounting boss on the planer but there is still adequate support for the bushing retainer. Fortunately I got the remaining screw out & there is plenty of thread in the hole to grab when I re-assemble later today. I am considering building up the boss w/ 2-part epoxy & then re-drilling & tapping. I'm no help, but I do hate it for you.


Ted

Your fix with the epoxy is near perfect except the forces on the boss may cause it to expand and release the epoxy. To overcome that it is best to drill and tap it for a Heilcoil.
This is an insert that looks like a spring after it is installed it will be stronger than the original threads. The spring wound coil will not allow expansion.
Heilcoils are available in kits with the drill, tap and insertion tool dependant upon the original thread size.
It isn't a cheap fix but it is peramant and cheaper than replacing the planer.

[ted van halen]

Your fix with the epoxy is near perfect except the forces on the boss may cause it to expand and release the epoxy. To overcome that it is best to drill and tap it for a Heilcoil.
This is an insert that looks like a spring after it is installed it will be stronger than the original threads. The spring wound coil will not allow expansion.
Heilcoils are available in kits with the drill, tap and insertion tool dependant upon the original thread size.
It isn't a cheap fix but it is peramant and cheaper than replacing the planer.

Max,
The helicoil was my first choice, but there is not sufficient "meat" to drill & tap the helicoil into. I was thinking about cross drilling a couple of extra holes that would give the epoxy a mechanical bond as well. What I actually did was to just re-assemble it as-is & it seems to be okay. Fortunately there was enough extra thread in the bottom of the hole to use a longer bolt.



Ted

[rfisher7381]

Recently I broke off a screw extractor while trying to remove a stud. I tried drilling with a variety of drill bits with no success. I was getting desperate and chucked up a masonry bit (carbide tipped) and it worked. Not real pretty and make sure your wearing safety glasses as I think it chipped off chunks of the screw extractor as it bored down.

[Stick]

Thom2's grandfather taught him right. There are many good power tapping attachments made for use in drill presses and milling machines, but I wouldn't use one on a hand drill. The most common mistakes people make with taps is not using cutting oil, or not enough, or the wrong kind for the metal, using dull taps or the wrong type of tap and using the wrong type of wrench. Using an adjustable (Crescent) wrench on a tap is an almost sure fire recipe for breakage. Tap wrenches need a t-handle so that there is force equal on both sides. This helps keep the tap straight. There are three taps that make up a set, taper is used to start threads, plug to finish through threads, and bottoming to cut threads to the bottom of a blind hole. Unfortunately, most assortments only come with taper taps, so most people don't even know the others exist. Taps designed for power use are different again.

[ted van halen]

make sure your wearing safety glasses

Ain't that the truth. I was drilling (w/ a hand drill) an exhaust stud from a manifold years ago. I walked right past my glasses on my way to the bench where I had it clamped up. I was standing over it drilling when a HUGE chip popped up & stuck in my eyebrow about an inch above my eye. I literally had to pull it out. Not only was it embedded in my foreheaed but it was smoking hot. No doubt in my mind I'd have been blinded had it been just a little lower. I put on ANSI Z87(I think) glasses when I walk in the shop now.


Ted

[guycox]

That's the way I do it..

I think Lorings point is that you can't 'feel' a tap when using a power drive, I never use a power tool to drive a tap, never have, never will. Whenever I'm tapping steel with full threads, I turn the tap no more than 1/2-1 turn, then back off at least 1/4-1/2 turn. I know this is probably overkill and many will tell me I don't have to do it this way, but this is how my machinist grandfather taught me and how I've always done it. The 1/2 turn insures a small bite, backing out a 1/4 turn insures the threads are cleaned up and the chips ejected from the tap and also allows the tap to 'relax'. I've never broken a tap doing things this way and I'm not about to take my chances at changing now. I know doggone well that if I break a tap off, it'll be the day that I'm out of #3 on that list

The 1/4 backing out part of the process breaks the chips. If the chips aren't broken they'll wrap themselves around the tap and soon the friction of the tap and the chips against the clear will overcome the torsional strength of the tap..

Another way to remove a broken tap is weld a hex nut over the broken tap if it is at or slightly below the surface... then after the weld has cooled heat the job rapidly and back the tap out with vise grips.