help! i broke a 1/4" tap

[mozeppa]

as the title said...

was cutting 1/4" threads and was about 1/2" deep into the metal and.......snap!

is there any way to get the stub out with out too much damage?

is there a drill that'll even touch tool steel?

[country gent]

How many flutes does the tap have? There are broken tap extractors that fit into flutes and will sometimes turn them back out fairly cleanly. WHat kind of metal? Blind hole or thru hole? bottomed out or chip bound? Slowly vibrate tap and blow with compressed air you want to get as many chips out as possible before starting. Carbide will cut hardened tool steel but not easily and its not cheap. I have worked broken taps out with a 1/8" carbide burr and high speed pencil grinder It is a long slow touchy process. Depending on depth hardness part fine vibration (electric pencil) will chip up the tap. Dead easiest is an edm machine and an appropriate electrode.

[lowallman]

If you have a left hand drill available in tap drill size
and go at slow rpm it may catch and raise the tap, with some luck.

[Bradley09]

Is It flush with the material if so you could try tig welding a shaft or bolt onto it

[nhrifle]

I have never been able to get tap extractors to work. I always end up with more problems than when I started. As stated above, carbide will cut the tap, but you are in for a fight. The best way I know of to deal with a broken tap is to take advantage of its hardness and shatter it. If you have access to a torch, you can heat the part, concentrating the heat on the tap, and when hot plunge into ice water, then use a pointed punch and give it a sharp rap. If you are lucky this will cause it to fragment.

You can also take a small cold chisel and hammer and give it some taps around the circumference of the tap to try and spin it out of the hole until you can grab it with pliers. Be sure to use a good penetrating oil for this.

[joesig]

Shattering it unless you wish to farm out to EDM, etc. Shattering is easier with the high carbon taps. The high speed steel ones don't shatter too easily. You'll be grinding the chisel often. :-(

For future reference, I have had great luck with two flute spiral point taps.

[DougGuy]

I have actually cut taps out with a cutting torch. I found out if I hold down the cutting oxygen and very quickly flash the hole, the tap will literally oxydize in seconds leaving the hole unharmed, but you gotta be quick and I mean very quick, it takes less than 1 second to turn white hot and melt, less than 3 seconds to blow it out. It works best in a blind hole, where oxygen is forced down one side of the tap, and forced back up the other side. If it is a through hole, clamp something on the bottom of it to make it blind.

[halfslow]

I broke one in aluminum.
Went to to Harbor Freight and bought this:
http://www.harborfreight.com/power-tools/rotary-tools/80-piece-rotary-tool-kit-97626.html
Used up all the diamond burrs, but managed to cut it in pieces and remove them without screwing up the work piece.
You don't have to totally turn the tap into dust, just remove material so it can be moved.
Obviously, a four flute tap is gonna be more work than a three flute one.

If you run out of diamond burrs, they have more:
http://www.harborfreight.com/20-Piece-18-Shank-Rotary-Diamond-Point-Tips-69653.html

It helps to have a small pair of round nose pliers to work the pieces out.

[JWFilips]

Damn! Never broke a 1/4 " tap Hope it was carbon: otherwise not sure what you can do....watching this post!

[zuke]

How much work do you have invested in the piece?

[DCM]

Best method is EDM
Next best is the quote below. I don't know what it broke off in but drilling will most likely make matters worse unless you have enough experience and the right tooling, but if you did I doubt that you would be asking here.


I have never been able to get tap extractors to work. I always end up with more problems than when I started. As stated above, carbide will cut the tap, but you are in for a fight. The best way I know of to deal with a broken tap is to take advantage of its hardness and shatter it. If you have access to a torch, you can heat the part, concentrating the heat on the tap, and when hot plunge into ice water, then use a pointed punch and give it a sharp rap. If you are lucky this will cause it to fragment.

You can also take a small cold chisel and hammer and give it some taps around the circumference of the tap to try and spin it out of the hole until you can grab it with pliers. Be sure to use a good penetrating oil for this.

[gunshot98]

105730Go to your local Hardware store. They should have these in stock. Get the size you need, 1 smaller than the tap. It will drill out a tap, they are super hard. Don't know what kind of equipment you have or experience. All jokes aside this is a delicate job. Might want to take it to a Gunsmith that has done this before. Found these bits a few yrs ago and keep them in my drawer all the time. Pics would help in helping us help you.

[enfieldphile]

I have done it w/ a diamond bit in a Dremmel tool.

It's slow work! It takes a steady hand. But done carefully it works well.

[oldred]

I have removed a LOT of broken taps over the years when ham handed mechanics would break the darn things then turn the job over to the welders, I got tagged for the job more often than not.


Nhrifle's suggestion of heating red hot with a torch (this requires an Oxy/Acetylene torch, propane or mapp is useless for this) then quenching with ice water is by far the easiest way if this is a high carbon tap. They will usually shatter in small pieces when hit with a punch but several problems could be encountered with this method. First is this a carbon tap? A HSS tap will not shatter like a carbon tap and indeed they are meant for high heat strength so don't attempt that method if this is a HSS tap you are dealing with. Then of course there is the question of just what it is the tap is broken off in, is it a gun part? Is the metal heat treated and thus should not be heated due to changing it's temper/structure? The dremel tool/die grinder with a diamond burr is slow but often the best method if the heat and shatter trick can not be used, I think I have tried every trick in the book since this was an all too common occurrence at the mine maintenance shop where I worked.

Hopefully this post is too late and you already have the darn thing out, best of luck to you!

[atr]

You can also take a small cold chisel and hammer and give it some taps around the circumference of the tap to try and spin it out of the hole until you can grab it with pliers. Be sure to use a good penetrating oil for this.


This would be my first approach. It has worked for me.

[w5pv]

I have used needle nose pliers with some sucess turning a broken tap out,Next I would silver solder a washer on it if possible and then a nut this will work also.

[Hardcast416taylor]

A buddy told me the story of a tool & Die shop supervisor who would have apprentices drill 12 holes on a piece of 1/2" cold roll steel plate then have the apprentice tap each hole using older used taps and leave the tap in each hole. When done he would inspect the tap work then with a hammer break off all the taps! He then told the shocked apprentice to remove all the broken taps as a lesson in removing such an occurance! Quite a cruel and hard lesson I would say.Robert

[joesig]

A buddy told me the story of a tool & Die shop supervisor who would have apprentices drill 12 holes on a piece of 1/2" cold roll steel plate then have the apprentice tap each hole using older used taps and leave the tap in each hole. When done he would inspect the tap work then with a hammer break off all the taps! He then told the shocked apprentice to remove all the broken taps as a lesson in removing such an occurrence! Quite a cruel and hard lesson I would say.Robert
Sound like the shop supervisor was trying to see if the apprentice could teach him some new obscenities!

At least they were 1/2" and not broken off while driving. I bet that would be fun with 4-40 or smaller.

[Char-Gar]

If the tap is removed or not, there is a lesson here. Taps break when the user doesn't back it out every few turns and clear the chips. Once if squeaks and stops on the chips, you are done for. Don't let that happen.

[joesig]

If the tap is removed or not, there is a lesson here. Taps break when the user doesn't back it out every few turns and clear the chips. Once if squeaks and stops on the chips, you are done for. Don't let that happen.

That is true.

I don't have a ton of experience with various taps. I only used my grandfather's (1930's) taps a little when I was younger and they held up pretty well to my youth and inexperience. Maybe that old can of oil helped.

The torque required with new SNAP-ON taps is quiet a bit more. Clearing chips every half or full turn doesn't help as much as one would expect. It could be the new oil or maybe the design. I am amazed how well the inexpensive Enco spiral point or spiral flute taps cut! Maybe those designs are cheating vs the skill of a real machinist but I must say, they sure do make life a lot easier.

PS little taps break when you put any lateral pressure on them. :-(

[country gent]

Taps broke from lateral pressure are much easier to get out than taps that are bottomed out or chip bound. On a 1/4" tap I ussually go 1/2-3/4 turn back up and twist back and forth a couple times to help clear chips then another 1/2- 3/4 turn and repeat. A good accutrate chamfer on both sides of the hole helps alot also. Another trick with blind holes is to fill hole with wax or grease as tapping the wax pushes up and out carrying chips with it. We used spiral gun taps on thru holes but in a blind hole they just forced the chips into the bottom of the hole plugging up. We would also mount smaller taps in a drill press and use it as a tapping stand turning chuck by hand.
Removing a broken tap can be done several ways drilling works but you seldom have a flat true surface to drill into and the drill will walk. An carbide endmill does much better if you can get the part into the mill solid. Working with a small pick and tapping to chip break the tap will work but requires skill patience and time, the die grinder with a diamond grit or carbide burr works well and with skill and good light does a great job. Done properly you can cut thru the web of the tap and pull the actual thread sections out one at a time. I have done this before on machine members that couldnt be removed. Working slow and easy is the key. Another trick of the trade is using left hand drills and cutters as they tend to loosen the tap bolt rather than tighten it. The first step is getting chips out and the hole clean so there isnt anything to bind up once it starts to move.

[nhrifle]

A buddy told me the story of a tool & Die shop supervisor who would have apprentices drill 12 holes on a piece of 1/2" cold roll steel plate then have the apprentice tap each hole using older used taps and leave the tap in each hole. When done he would inspect the tap work then with a hammer break off all the taps! He then told the shocked apprentice to remove all the broken taps as a lesson in removing such an occurance! Quite a cruel and hard lesson I would say.Robert


That's just evil!

[CastingFool]

I once had a summer job at a large manufacturing plant. I worked in the salvage dept, burning out broken taps and drills. Used an EDM machine to burn them out. Sometimes, the threads would be all messed up, so I would have to have the holes welded up, then I would lay them out again, drill and tap. Small taps such as 1/4" were definitely a challenge. Sometimes, if the hole being tapped is a through hole, using the appropiate tap extractor from the opposite side works better than working from the broken side.

[John Taylor]

I work a lot with small taps and usually brake at least one a month. I don't have an EDM but I do have a good milling machine. Using old broken carbide end mills ground to a chisel point works great. Need a ridged setup and run them fairly fast you can bore a hole through the middle of the tap to the bore diameter of the original hole. Works great on 6-48 taps in hard actions, the most common broken tap in my shop. Saw a demonstration once where a guy drilled a hole in a HSS bit this way. Just need to be very careful not to brake the carbide off in the hole.

[Stonecrusher]

Country Gent and John Taylor are right on. Trying to break high speed almost always results in a messed up hole. EDM is easiest, if you have it. Carbide drills and endmills work but I always seem to break the carbide when I come out the other side of the tap so wind up picking out the pieces of carbide.

One time I broke a tap off in a rifle barrel, and it was an odd size that I didn't have a carbon steel tap for(clean out screw in a muzzleloader). I couldn't budge it. I thought a while and came up with an idea. Use a ball shaped carbide burr but hold it in a collet and use as a drill. I run about 700RPM and use light pressure on the quill clearing the fine chips frequently with compressed air. This works better than anything else that I have seen. The burr will walk right through the tap in a couple of minutes and does not break when exiting the opposite side. Be sure to use a burr that cuts to center. A 1/8" ball on 1/8" shank will work for #8 to 1/4" The burr need only cut through the web of the tap but you might need a 3/16" ball for 1/4". Works for bigger taps as well, there just aren't many on a firearm.

I've never seen anyone else do this but there's nothing new under the sun. Eliminates a lot of the need for skill needed when trying to grind tap out freehand. I guess you could do this in a drill press but never tried. The drill chuck needs to run pretty dang true to keep from snapping the shank, that is why I always used a collet to hold.

If you don't have a mill or at least a good drill press, things are much more difficult.

[Kilroy08]

I've gone the carbide endmill route before. Clamp it securely and crank that Bridgeport up as fast as it will go. GENTLE downward pressure on the quill is the way to go. Wear hearing protection in addition to a full face shield. Even with ear plugs in, the sound will still set your teeth on edge.

[mozeppa]

thanks guys ...i appreciate all the input.

update: i boogered it up and had to replace it. only 20 bucks...and not a gun! (re-load equipment related)

[longbow]

Here's another method that works.

I broke off a tap in a 327 block and tried the cold chisel method along with a few others with no success. I decided I would try using a carbide bit in my Dremmel and lo and behold, that carbide bit cut the HSS tap right out of there. It takes a steady hand so you don't hit the threads but the carbide bit worked very well and was still in good shape when I finished.

The only carbide bit I could find locally was actually for tile cutting. It is 1/8" diameter and cost me $20.00. It has quite coarse "teeth" on it but it held up fine.

Longbow

[Col4570]

Before you think about pounding on the Tap,try this a piece of spring wire that fits into the Flutes,Bend double to fit opposite flutes turn the wire back and forth and look for movement,keep moving back and forth until the Tap turns out.A blast of air helps to clear the hole.

[W.R.Buchanan]

I am pretty good at removing broke taps. But I am also really lucky. I have to say luck is always senior to skill when it comes to tap removal. [smilie=b:

When I drilled and tapped the receiver of my 03A3 action I broke the same $26 6-48 tap 4 separate times while doing the two holes. In each case I was able to use a punch made from a drill blank and shatter the tap end and then regrind the end for the next hole. I did this 4 times in a row successfully. This was all done on a mill with the tap handle in the spindle and two fingers turning the handle. No better setup exists.

I had ground thru the exterior case hardening with a grinding point since a carbide drill wouldn't touch the surface. I was able to tap threads thru until the tap had to break thru the case hardening on the inside of the receiver where it would break. The third time thru I would get all the way thru. All the while sweating blood!!!!!

This happened the same way on both holes and I lost 10 lbs. in sweat. Took 2 hours + to drill and tap 2 holes! :holysheep

I make no claims to be better than 60/40 on tap removal,,, 40% being the success rate. However this is one place where it is definitely better to be lucky than good.:mrgreen:

Randy

[HotGuns]

I remove broken taps quiet often. So far, the biggest one was 3"-4 TPI on a turbine feed pump. The smallest yet is a 3-56 used for installing a shotgun bead.

I've tried every method ever printed and some that weren't. One that works the best is to use an I-Roc drill either in the milling machine or with a very rigid mag based drill. I-Rocs are solid carbide, two fluted drills that will blow right through a tap. The key is to use high speed and to advance the tap no more than one diameter at a time, clearing out the hole with and air hose. High speed, light pressure and its best to start on a surface that is square. Since few taps that break are actually broke cleanly, its best to use a small burr bit to remove any angle on the break.

I-Rocs aren't cheap, but well worth it for broken taps on expensive pieces. The thing is, the setup must be rigid. If all you have is a typical hand drill that runs slow, forget it. You'll just break it off.

[David2011]

I bottomed out and broke a 6-48 tap recently. It was easily removed with a center cutting carbide end mill. It helped to have a milling machine. At a minimum I would want a stiff drill press with a 2 axis vise.

David

[MBTcustom]

I buy a lot of 3/32" four flute carbide endmills. I think they use them for circuit boards or something. I get them from E-bay and they all have this green plastic collar around them.
Anywho, If I break a tap, the first thing I do is try to remove it with pliers which never works, but it makes me feel better to punish the tap by breaking it's freakin teeth out. (whew! Ok, I'm fine, I'm cool!)
The next level is to use the 3/32" endmills in the milling machine, by using the stop micrometer to advance about .003 per hit and slowing eat that sucker away.
Unfortunately, I use really really good quality taps that don't like to cooperate, so after doing the quintessential turning my cigar into ash with one draw, and hurling of the broken endmill accross the shop, I move to step 3 which is to bust out the diamond burrs and the dremel tool.
This usually works, especially if you lubricate the diamond burr with a blue streak of bad language and cigar smoke.
Once the tap is finally out, it's time to try it again, but this time with sweet talk, and promises that if this tap will help me, I'll put it in a velvet display case in a place of honor and never ask it to do such a nasty job ever again in its life and yes it is a very special tap, and very beautifully ground too...........

LOL!

[W.R.Buchanan]

Tim: in other words,,, "It's better to be lucky than good!"

Randy

[M-Tecs]

These work well http://www.omegadrill.com/

[John Taylor]

Tim: in other words,,, "It's better to be lucky than good!"

Randy
The old saying is " If you got luck you don't need brains".

[KCSO]

I either use Dougs method shown to me by Doc Carlson many years ago or I use a freebie from the local dentist. He gave me a handfull of old carbide bits and in a dremel they eat a tap alive. Cut the web in a couple spots and a light tap with a punch and the shards fall out. For small taps you just eat right through the center.