how to remove a broken tap from a hole

Removal of a thread tap broke off


Removing broken bolts/screw is one of those pesky jobs that few people look forward to.

The manual methods for removal of deep broken bolts is to drill them out, a left hand drill bit and a reversible drill.

Step 1: drilling holes, drill a small hole first, then drill a larger hole through the broken fastener. It¡¯s easier to drill centered and straight by using a small drill first, but be careful not to break the small drill

Step 2: flatten the surface at the end of the broken bolts/screw. Where bolts have broken. which will insure the drill bit not to wander off-center, when attempting to drill the hole. we used a grinder to flatten the surface at the broken stud. When a bolt is broken off below the surface of a threaded hole, a jagged break often can be flattened with punches to get a better surface for drilling.


Step 3: then can use the screw to remove it

The machine methods for removal of deep broken bolts is to drill them out, TR800W EDM remove broken tap/ bolt .

The method to drill hole:


Through the electric erosion principle punch, and the tap can easy remove.
 
You can't drill a tap out with a regular bit. The tap is as hard or harder than the tap. You would have to get a carbide drill bit to drill it out and because of the shape of the tap it's very hard to do. The bit wants to slide off the side where the threads are. You end up wallowing out the metal you are trying to tap and in the end have to drill a much larger hole and tap a lot larger size than you wanted. If it would work in your situation to drive the tap through with a punch then you could drill and tap to the next larger size.
 
If there are exposed threads above the broken bolt/cap screw, then take a bolt and drill a hole threw the center of it. If you have a lathe this will be easy, then screw it into the hole above the broken cap screw and then drill.
If there are no threads, then a short rod that will fill the hole.

Dusty
 
Started as spam but gives me a chance to share. I hold another bolt off to one side and weld it to the broken bolt. The bolts don't have to be in line and it makes welding a lot easier.
 
I agree taps basically cannot be drilled. Even if you use carbide there is a good chance it will be chipped because carbide does not like interruptions in cuts. However taps are brittle enough that sometimes you can take a good center punch and bust them. After this just remove the small peices with needle nose if possible. They do make a tool called a tap extractor as well that has pins with a locking nut that slide into the fluted area of the tap.
 
Walton tap extractor for four fluted taps [ It is a set of extractors]. Or measure the heli-coil tap for that thread then if you can drill a series of small holes around the tap staying within the diameter of the heli-coil .Tap gets loose and can be pulled out and I think I'm talking to a spambot anyway .
 
If the broken tap is in aluminum, pour some Nitric acid in and it will eat away the ferrous metal. Then, pour some in the eyes of spammers.
 
All ideas or well intended advise is fine but all situations with broken taps are not the same. So with the situations not being the same it would seem that approaches to removing the broken taps might have to be different.
 
It happens. I have used many to the point where the metal fatigues, or they just plain wear out. Try tapping a four hundred 10-32 holes before lunch without breaking one.
 
If you tap enough holes you will break a tap. Try tapping a 1940s Harley frame . You need a box of taps for all you will break.
 

I'm in the mechanical trade. I've tapped plenty of holes in plenty of different types of material over the past 40 years and have never broken a tap.

Using patience and plenty of cutting oil works well for me.
 
Sometimes it just happens. Had one break yesterday while it was on its way back out of the hole. Wasn't a blind hole, either. Probably had a thousand holes with that tap, but it was working great right up til it snapped.
 
An old metal worker showed me a trick that is as scary as it is efficient: Blow it out with a cutting torch. Taps are high carbon steel. There is often a sharp point sticking up that helps the process. Get it red hot and hit the oxygen lever on your torch. This is all done so quickly it doesn't hurt the metal being tapped. The oxygen blows the broken tap out and you're set to go. I've done it; it's scary, but it works.
 
(quoted from post at 10:27:14 08/22/15) An old metal worker showed me a trick that is as scary as it is efficient: Blow it out with a cutting torch. Taps are high carbon steel. There is often a sharp point sticking up that helps the process. Get it red hot and hit the oxygen lever on your torch. This is all done so quickly it doesn't hurt the metal being tapped. The oxygen blows the broken tap out and you're set to go. I've done it; it's scary, but it works.

Thats what I do with cast iron if the tap wont come out easy with needle nose. Works great for bolt too if you drill them first , practice on scrap.
 
The easiest way is to use an endmill. If you have a 1/4" bolt use a .187 end mill. Or whatever is handy. Best start with a junk one first. And set the stop on the mill/press you are using so you only can push into it a couple .001 at a time/peck.

And for the guys who have never broken a tap....haha, you haven't tapped much OR you have new taps and easy tapping material.

Try tapping 316SS with an M2 tap, or 4-40. Its very difficult especially if in a blind hole where it must be bottomed
 
I once bought a brand new 3/8 tap to clean rust out of a few threaded holes. I put the tap in the first hole gave it a 1/4 turn maybe. And the tip broke right off!

Anyone who hasn't broke a tap. Has not threaded many holes. Even with cutting oil, they will break.
 
Time and patience. As I said, I've been using taps for many years and have never broken one. A lot of the stories on here tend to make me think that a lot of folks don't have much patience when it comes to doing stuff.

Believe me or not, I don't really care. A lot of folks on here post stuff that I don't believe so I guess it goes both ways.
 
(quoted from post at 11:23:35 09/05/15) Time and patience. As I said, I've been using taps for many years and have never broken one. A lot of the stories on here tend to make me think that a lot of folks don't have much patience when it comes to doing stuff.

Believe me or not, I don't really care. A lot of folks on here post stuff that I don't believe so I guess it goes both ways.
Congratulations-- you are better then me.
I am a 70 year old retired Tool&Die Maker, and I have broken many.
 
Gosh, Obso, what gives you the idea that a poster named "Trmedm Aldous" might be a scammer???
 
(quoted from post at 00:53:59 09/06/15)
(quoted from post at 11:23:35 09/05/15) Time and patience. As I said, I've been using taps for many years and have never broken one. A lot of the stories on here tend to make me think that a lot of folks don't have much patience when it comes to doing stuff.

Believe me or not, I don't really care. A lot of folks on here post stuff that I don't believe so I guess it goes both ways.
Congratulations-- you are better then me.
I am a 70 year old retired Tool&Die Maker, and I have broken many.

I'm not saying that I'm better than you or anyone else, I just spoke of my methods, experiences and results.
 
Lots of us have patience, but its also different when you are being paid or making money to tap a hole(s). Yeah none of us will break a tap if we take all day and turn it 1/100th of a turn and back it out and go again.

Also, when you say you haven't broken one....many of us haven't broken too many 1/4 and above taps I'm sure. I'm wondering how many smaller taps (say 10-32, 8-, 6-, 4-40, M2, etc) you've actually used.

And on another note, I must again add that some of us (me) aren't tapping these into 1018 or cast which is cake work. I'm tapping into tool steel or hardened tool steel 4140, or sometimes aluminum and/or copper can be tough.

For those of us in the real world, it DOES happen and it actually happens more often than you think in a shop. The trick is to not let it take all day to fix it. I'd say in 90% of the cases we can fix it in less than 15-20 min and the thread is still adequate. It will not be good in my opinion by blindly hitting a punch around in the half threaded hole!
 
Running taps in a tapmatic on a mill or drill press is a numbers game. You can only tap so many holes before the tool dulls and jams. Sometimes they break. You can buy the best and keep them oiled, but they call them "consumables" for a reason.
 
I think one of the greatest causes of broken taps is that some people use a crescent wrench or other type tool.
You are less likely to break a tap by using the proper size tap wrench. A close second would be improper hole size along with improper lubrication.
 

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