I did some drill and tap tonight. First time I've done this and on my newest rifle to boot, so it was a little exciting. It went well but the whole time I was running the tap in I was praying that it would not break. If it had, where would that have left me? Is there a tool that will remove a broken tap? And taps being fairly cheap, how long do you reuse them? These were 6-48 holes BTW.
Broken tap removal
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zxcvbob
Member
There are special spanner wrenches you can get with little pins that fit in the flutes of a tap and let you back it out. A #6 is kind of small for that tho'
If that doesn't work, you might have to get it ground out with a diamond bit on a dental tool, or burned out with a laser or electro-something (can't remember what that one's called)
If that doesn't work, you might have to get it ground out with a diamond bit on a dental tool, or burned out with a laser or electro-something (can't remember what that one's called)
dfariswheel
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The usual gunsmith method is to use a sharp center punch to shatter the tap.
Put the punch on the tap and give it a sharp blow with a steel hammer to break the tap into pieces.
Then use a needle to pick the broken pieces out of the hole.
Put the punch on the tap and give it a sharp blow with a steel hammer to break the tap into pieces.
Then use a needle to pick the broken pieces out of the hole.
scrat
Member
one rule of thumb penetrating oil. do not use a tap or die without it. you need to keep the threads lubed. Pretty much what bob said is true. Other than that a vise. penetrating oil. and some picks and needle nose pliars the really really thin type. You would have to pic at it turning it in the opposite direction until you can get a piece of it to unscrew. When doing this though. You have to make sure you turn it enough to really get at it. Otherwise if you turn it out just so you can grab it with a pair of pliars then mar up the end. Well guess what you could have also pinched the tap making it harder to unscrew. so turn it out further.
thunderstorm
Member
A machinist turned me on to Tap Magic a couple of years ago, not sure how it would affect finishes but from a thread cutting perspective nothing beats it. I only wish that information like this was not in hindsight, sorry to hear the tap broke.
Sam
Member
I would give you this advise.
Until you become very skilled at tapping, stick with plain carbon steel taps.
They are very brittle compared to HSS taps and if you break one it is much easier to shatter and remove.
I always did that with my students and got a better results at lower cost.
Always use a lot of lube
Sam
Until you become very skilled at tapping, stick with plain carbon steel taps.
They are very brittle compared to HSS taps and if you break one it is much easier to shatter and remove.
I always did that with my students and got a better results at lower cost.
Always use a lot of lube
Sam
zxcvbob
Member
Lot's of good advice, tools and techniques here. Thanks guys. Just to be clear though, my tap did not break. Not this time anyway. But I could picture it happening and sooner or later it probably will.
Looks like there is still hope for a do it yourselfer.
Looks like there is still hope for a do it yourselfer.
Chawbaccer
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If you do break one, do not lean over it, the tears will cause it to rust and make removel more difficult.
I am not sure of Scrat's definition, but do NOT use what most folks call penetrating oil (a thin oil to penetrate crevices and crud). Use only cutting oil specified for tap and die use. This is a thick oil (some are close to a grease) that will adhere to the tool and speed the process.
Also, don't try to cut too much at once. In tapping, 1/4 turn is probably too much; take it slow, and back up frequently to break the chips. Plus, in a deep hole, remove the tap entirely about every turn or two, flush the hole and continue.
It is mainly a lot of feel and experience; there is no advice anyone can give you on here that will guarantee you will have no problems.
Jim
Also, don't try to cut too much at once. In tapping, 1/4 turn is probably too much; take it slow, and back up frequently to break the chips. Plus, in a deep hole, remove the tap entirely about every turn or two, flush the hole and continue.
It is mainly a lot of feel and experience; there is no advice anyone can give you on here that will guarantee you will have no problems.
Jim
rcmodel
Member in memoriam
A tap guide can also help prevent a lot of broken taps. Especially in the smaller sizes.
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6748&title=TAPRITE TAP GUIDE
I made my own out of square steel or brass blocks drilled for slip-fit tap clearance. I have also made them out of 1/2" bolts by facing off the head to make it flat & square, then center-drilling a hole in the cut-off shank.
rcmodel
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6748&title=TAPRITE TAP GUIDE
I made my own out of square steel or brass blocks drilled for slip-fit tap clearance. I have also made them out of 1/2" bolts by facing off the head to make it flat & square, then center-drilling a hole in the cut-off shank.
rcmodel
kimbernut
Member
Broken tap removal tools
I experienced my first broken tap during tapping the top strap of my S&W mod.28.
I was given a co. name of JTS machine tools and ordered the proper size tool. It worked like a charm. I understand ENCO also carries the same tools.
I experienced my first broken tap during tapping the top strap of my S&W mod.28.
I was given a co. name of JTS machine tools and ordered the proper size tool. It worked like a charm. I understand ENCO also carries the same tools.
nalioth
Member
As dfariswheel said, smack it with a center punch.
The tap is brittle and will shatter.
Don't spend any money on specialized equipment, imho.
The tap is brittle and will shatter.
Don't spend any money on specialized equipment, imho.
jim147
Member
In several years of doing machine work I have no idea how many taps I have removed. Most of these brought in by customers but I broke my share whit some days tapping 50-100 holes.
I have used many ways to remove these depending on how it what broke and what it was broke in. Welded nuts on some, ground some with diamond burrs, annealed and drilled, but the most common was always shattering then picking out the rest.
When you tap firearms you usually have to deal with hardened steel. So if you don't have a known good tap then go buy a new one. The expense is well worth the trouble saved.
I have used many ways to remove these depending on how it what broke and what it was broke in. Welded nuts on some, ground some with diamond burrs, annealed and drilled, but the most common was always shattering then picking out the rest.
When you tap firearms you usually have to deal with hardened steel. So if you don't have a known good tap then go buy a new one. The expense is well worth the trouble saved.
jwr747
Member
EDM machines to burn out taps ,the same machine that does Magna-Porting,or cutting the slots in rifle/pistol barrels. EDM = electro discharge machine, I think. jwr
PS: by the way,a EDM machine is a hoot to play with,just wonderful what they can do.
PS: by the way,a EDM machine is a hoot to play with,just wonderful what they can do.
Clipper
Member
If you have a vise for your drill press, a carbide ball-nose end mill, run at max RPM and fed carefully, will remove the center of a broken tap or drill, and allow for easy removal of the flutes. Don't try it if you can't hold the work 100% rigid, and never try it with a hand drill!
One trick if you can do it, is to start with a tap with the same threads (tpi), but a size under what you want. It will partially cut the threads without much strain, since it is not cutting the full depth, then the full size tap will cut the rest, again without much strain since the cuts have been started.
Also, if you need to use a bottom tap, you will have to start the hole with a chamfer tap. If it is a "one off" job, you can buy the chamfer (plug or taper) tap and then after the holes are well started, grind the end off the tap (making sure it doesn't overheat) and use it as a bottoming tap.
Jim
Also, if you need to use a bottom tap, you will have to start the hole with a chamfer tap. If it is a "one off" job, you can buy the chamfer (plug or taper) tap and then after the holes are well started, grind the end off the tap (making sure it doesn't overheat) and use it as a bottoming tap.
Jim
jmorris
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http://www.tapmatic.com
Will make broken taps a thing of the past.
http://www.electroarc.com
Has what you need if you want to be in the business of removing broken taps, EZ-outs etc.
I even have an old article on how to make one of the metal disintegrators using a drill press, hand held engraving tool and a DC arch welding power supply.
Machine tapping, if done correctly will reduce broken taps (not to mention crooked holes). Remember plug, taper and bottoming taps are not very suitable for machine tapping. A spiral point or a spiral flute tap is the best choice.
FWIW I don’t use taps that you could hit with a hammer and they would "fall apart", That would be asking for trouble from the start.
Will make broken taps a thing of the past.
http://www.electroarc.com
Has what you need if you want to be in the business of removing broken taps, EZ-outs etc.
I even have an old article on how to make one of the metal disintegrators using a drill press, hand held engraving tool and a DC arch welding power supply.
Machine tapping, if done correctly will reduce broken taps (not to mention crooked holes). Remember plug, taper and bottoming taps are not very suitable for machine tapping. A spiral point or a spiral flute tap is the best choice.
FWIW I don’t use taps that you could hit with a hammer and they would "fall apart", That would be asking for trouble from the start.
machinisttx
Member
That's really a matter of opinion and the material being tapped. I don't particularly like Tap Magic and won't use it if sulfurized cutting oil is available. If you're tapping cast iron, use kerosene as a cutting oil.
Broken tap removal tools are hit and miss. Sometimes they work and sometimes they just break which compounds the problem. I've never had good luck with them and don't even bother trying them anymore.
Sometimes if the tap isn't stuck too badly you can use a hammer and punch to back it out of the hole. If that doesn't work, a carbide endmill will cut that dude into dust. There is also the option of EDM removal with either a hole popper drilling type machine or the possibly more common RAM type machine.
I've used a lot of methods and sometimes a combination of them to get broken taps out. It sorta just depends on the situation as to which one is best or gets tried first.
O rly? Spiral point taps push the chips ahead of the tool, which is fine for through holes, not so good for blind holes. Spiral flute taps are great for gummy and/or soft materials(aluminum for example), but don't work very well in hard alloys and are more prone to breakage since they're even weaker than straight flute taps. The other types work just fine with the proper cutting oil/coolant mix.
Thread milling for the win--100x better than tapping.
For some applications, a carbon steel tap is desirable. They will work just fine with the proper cutting oil and are easier to break up if one does snap in the hole. HSS taps can be a major PITA to get out in some situations.
Sounds like I was lucky. These were through holes so I used a taper tap all the way. I wasn't sure how far to cut before backing off and I was shooting for 1 turn. Generally it started flexing at about 3/4 and didn't back up too easily. Next time I'll break the chip more often. And finally, my "cutting lube" was an old can (remember those?) of transmission fluid. 
Well we got through it. The gun is a .22 and maybe softer than a high power rifle. That probably helped.
Well we got through it. The gun is a .22 and maybe softer than a high power rifle. That probably helped.
FrankRochester
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- Mar 1, 2007
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+1 for thread milling!
Spiral Point Gun taps for open holes
Spiral flute or Roll form taps for blind holes
As a matter of fact, I haven't used a spiral flute tap in I don't know when.
I only use gun taps or roll form taps.
If I have to, I grind down the huge lead on the end of the gun tap so I can run it deeper and still have room for chips.
I know alot of guys in the trade that will only roll form threads. They claim they give the best tool life on stainless steels, etc.
Proper steps for good hand tapping
1st thing, use the proper tap drill size!
2nd thing, use a quality tap. And a good tap wrench.
3rd thing, apply some Tap Magic into the hole.
4th thing, use a tapping block to guide your tap in straight.
5th thing, go a couple turns at a time and then back out the tap a turn to break the chip. Then proceed deeper.
6th thing, continue the process untill you get it to the desired depth. If at any point the tapping begins to feel more difficult, backout the tap and blow out the hole and re-apply tapping fluid. Also, check to make sure you haven't run out of space in the hole(bottomed out) before you go any further.
With smaller taps, I'd say around 1/8" in size or smaller you have to start to really take it easy. Don't force it to keep cutting. Take your time.
Spiral Point Gun taps for open holes
Spiral flute or Roll form taps for blind holes
As a matter of fact, I haven't used a spiral flute tap in I don't know when.
I only use gun taps or roll form taps.
If I have to, I grind down the huge lead on the end of the gun tap so I can run it deeper and still have room for chips.
I know alot of guys in the trade that will only roll form threads. They claim they give the best tool life on stainless steels, etc.
Proper steps for good hand tapping
1st thing, use the proper tap drill size!
2nd thing, use a quality tap. And a good tap wrench.
3rd thing, apply some Tap Magic into the hole.
4th thing, use a tapping block to guide your tap in straight.
5th thing, go a couple turns at a time and then back out the tap a turn to break the chip. Then proceed deeper.
6th thing, continue the process untill you get it to the desired depth. If at any point the tapping begins to feel more difficult, backout the tap and blow out the hole and re-apply tapping fluid. Also, check to make sure you haven't run out of space in the hole(bottomed out) before you go any further.
With smaller taps, I'd say around 1/8" in size or smaller you have to start to really take it easy. Don't force it to keep cutting. Take your time.
machinisttx
Member
Transmission fluid is not cutting oil, neither is WD40, or any of the other crap folks try to use. Proper cutting oil(Brownells "Do Drill", tap magic, etc.) and a new, spiral point taper tap would have more than likely kept the tap from breaking.
Using the wrong substance as cutting oil generally leads to torn threads, broken taps, dull taps, and a ton of other problems.
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