Broken 1/4" tap in through hole

[PT Doc]

I broke a 1/4 20 hand tap in a v block thread. it's a thru hole but nothing sticking out on either end. would a Walton 4 finger tap extractor work? Is it worth trying?

I have read up on some chemical metal disintegration at home on the stove on boiling water. Don't know the specific details but it's that an option. the v block is hardened. would like to try to keep current threads in fact.

I have a set of easy outs but getting a hole in the broken tap is unlikely since it is quite angled.

thanks for the help.

 

[PT Doc]

I don't have mill. that would be very helpful.

 

[zkling]

Where there preexisting threads or were you cutting new threads? Those finger tap extractors can work, but they are a bit fragile, in my experience in gummy materials like aluminum they can almost do more harm than good. Is is flush with the surface, proud or recessed? Have you tried a sharp pair of needle nose? Can you get into the flutes with them? How much of the tap broke off? It's usually a case by case basis for me.

If you have a tig welder you could burn it out, or if you know anyone with a wire or sinker edm could do the same.

 

[ihateminimumwage]

I've had good luck with my long skinny needle nose the few times I've broken taps. Hadn't seen those extractors before. Definitely going on my Amazon Wishlist.

As zkling put it, there's a lot factoring into how to handle it.

 

[theknurl]

google "broken tap removal service"

they EDM them out

 

[A_Pmech]

A Walton should work.

Buy extra fingers.

 

[PT Doc]

I saw the video of jerrys broken tap removal service. pretty sweet.

 

[PT Doc]

the threads were there just not all the way through. so I was trying to get them all the way through. I shouldn't of torqued that much but...

what is left is recessed. 4 flutes are clean. I might try center drilling again. Is that likely to ruin the carbide end mill? if that doesn't work then the Walton with heating the exterior around the broken tap and cooling the tap with inverted canned air will hopefully work. should I try soaking the tap remains in something?

thanks

 

[colin39]

Carbide and die grinder should have it out in no time

 

[zengarage]

How hard is hardened. You probably shouldn't have been trying to run a tap through it if it was hardened. If you can't scratch it with a file it is to hard to tap. If it is only the end I usually grind a point onto the leftover of the tap and use it as a punch to break it out. The only time those walton extractors work for me is if its not in there very good. If it is a good size piece you have some work on your hands with a die grinder or a bill from a shop that has an EDM or mill. But if your not careful you won't have usable threads left when your done.

 

[PT Doc]

How hard is hardened. You probably shouldn't have been trying to run a tap through it if it was hardened. If you can't scratch it with a file it is to hard to tap. If it is only the end I usually grind a point onto the leftover of the tap and use it as a punch to break it out. The only time those walton extractors work for me is if its not in there very good. If it is a good size piece you have some work on your hands with a die grinder or a bill from a shop that has an EDM or mill. But if your not careful you won't have usable threads left when your done.

I thought I was just going to extend part of a thread but it was likely more than that.

I will try the Walton with great on the block and freeze the tap. otherwise I'll pay a visit to the machine shop.

 

[Hpozzuoli]

Can you get a dremel in there with a grinding bit? I broke one years ago and was able to grind notches and use a flat blade screw driver to unscrew it.

 

[Farmall450]

Maybe try a left handed drill bit if you drill it?

Funny, I was just watching a video on tapping, old timer said toss the work piece if you broke a top in there...best of luck.

 

[PT Doc]

since the break is at an angle I haven't been able to drill a hole in the center. I tried a cobalt jobber bit butthere was too much flex.

for the dremel, what type of bit would be recommended?

 

[Hpozzuoli]

I don't know what either of the names of them are. Ones almost like a very small milling bit and the other is a very slim grinding bit. I hope you can see good enough in the pics.

 

[Hpozzuoli]

They came in this kit, but I am sure you can get them separately.

 

[bcradio]

you need a norseman bit

 

[FlyingLow]

since the break is at an angle I haven't been able to drill a hole in the center. I tried a cobalt jobber bit butthere was too much flex.

for the dremel, what type of bit would be recommended?

If it broke at an angle then drill from the back side on the end of the tap. It will turn the tap out when it grabs, no left hand drill required. Good luck, I know it *****. Only done that once...

 

[PT Doc]

If it broke at an angle then drill from the back side on the end of the tap. It will turn the tap out when it grabs, no left hand drill required. Good luck, I know it *****. Only done that once...

it technically it's a through hole but the v block has a notch on the side do to get to the bottom of the broken tap I would have to go through another hole.

I will try the dremel insert.

 

[Avgas]

I don't know what either of the names of them are. Ones almost like a very small milling bit and the other is a very slim grinding bit. I hope you can see good enough in the pics.

Carbine rotary file

 

[GRX]

Carbide and die grinder should have it out in no time

^^ this ... 1/8" double cut ball burr.

http://www.industrial-tool-supply.com/morse-cutting/Carbide-Burrs.html

 

[619DioFan]

Last time this happened to me I clamped the part in the vise and used my best drift and BFH to drive the broken tap piece out. was able to run a new tap thru to complete the threads. it worked.

 

[basspro]

I second a die grinder and bit. Sometimes a punch can get it to move. Could use an annular cutter and then install an insert.

 

[remileblanc]

No drill will touch a tap unless its a carbide drill. Has to be done in a mill.

Your best bet is to try to chip it away with a punch. A tap extractor may work.

 

[PT Doc]

you need a norseman bit

What type of Norseman bit solves this problem? Thnaks

 

[davethorik]

No drill will touch a tap unless its a carbide drill. Has to be done in a mill.

this. carbide drills don't even like drilling in hard materials like taps, so don't use a brand new carbide drill. the 1/8" shank carbide burs work well but even in a hardened v block the bit may bounce and hit the threads.

i work in a machine shop and a lot of our bench guys seem to like breaking taps off because i have to fix them. high speed, flood coolant, and use manual feed on the z axis is how i get broken taps out on my cnc mill (we don't have edm).

 

[Ruger_556]

Take a punch and hammer and drive it through. The threads on the tap will shear off and it'll shoot through the hole. Done it many times successfully.

 

[Westernhunter]

Take a punch and hammer and drive it through. The threads on the tap will shear off and it'll shoot through the hole. Done it many times successfully.

This!

 

[PugetDude]

A good quality punch, as close to the hole diameter as you can get (or grind)and a BFH should push it right out.The tap is hardened and the threads should shear off with a couple of good sharp blows. Use the shortest punch that will reach the bottom of the tapped hole, an off-center blow will just bend a long punch. Then clean up the threads-very slowly with lots of lubricant.

Good luck.

 

[FriendOfYours]

Get a low grade bolt, drill a hole through the center of it, insert in hole and use it as a guide to drill the tap

 

[artieb]

This is why I love this forum. FriendOfYours idea will last a lifetime of options, that I can pass to my grandsons.
You could cut the low grade bolt short, put a couple of thrust washers, use the pilot hole with the dremel bit, use the bolt to put pressure on the cutter.

 

[PT Doc]

Get a low grade bolt, drill a hole through the center of it, insert in hole and use it as a guide to drill the tap

I like this Idea. I have a few clean threads so that could work. What would you recommend I drill the tap with through this bushing! Thanks

 

[Steinmetz]

Last time this happened to me I clamped the part in the vise and used my best drift and BFH to drive the broken tap piece out. was able to run a new tap thru to complete the threads. it worked.

Last time I broke a tap I did the same. The remnant of the tap fractured and could be removed. It requires care, though.

 

[isr2kba]

Because your tap broke at an angle and you don't have the correct drill bit, I don't see a guide bushing helping out much.

In any case, you should start by eliminating the angle on the tap using the methods outlined by others. Then look at the prices of carbide bits or maybe a masonry bit in a pinch and decide on your next course of action. Finally consider whether you still need a drill guide or not.

PS a handheld drill is unlikely to work -- you'll need a DP or preferably a mill

 

[PT Doc]

Made some progress. In the process broke a punch tip off in the hole. Got that out now. Have a really sloped broken tap now. Maybe BFF will sort it out.

Used some canned air upside down and I think the hyper cooling was helpful. What I have realized that my punches and chisels are not really all that hard.

This is a tremendous amount of fun.

 

[PT Doc]

What size carbide end mill or masonry bit would I want to drill this using a 1/4-20 cap screw as a bushing. Pre drilling for easy out could work but I'd be up a creek if the easy out broke. I do theoretically have both side of the hole to work from. Like someone said earlier, from the underside a RH bit should back the tap out.

My v block looks like this

http://www.ebay.com/itm/Starrett-57...7?pt=BI_Tool_Work_Holding&hash=item2a33872273

 

[rsanter]

Use a dremel with a small grinding ball
Grind a notch in the center of the tap and knock off as much of the high part of the tap as you can
Use a small chisel in the notch you make to chip at the tap and start to break it into pieces

Bob

 

[isr2kba]

the final size decision is going to be dictated by how close to a perfect center you can get the drill.

Basically as big as you can while still staying comfortably inside the root of the tap. I'm assuming your final operation is to "crack" the remaining root/flutes apart for removal.

I don't see any path to success involving an ez-out.

 

[zengarage]

I think you are asking for new problems by trying some of these ideas. You can't cut something with a tool that is not harder than what you are cutting as you've kind of experienced with the broken punch.The jagged edged on the broken tap will chip the cutting edge of a carbide drill especially if you are not doing it in a mill to run it at high speed and control movement and feed. Carbide drills are expensive and you will turn them into scrap quickly. If you can't break it out or don't trust yourself to grind it out with a die grinder or dremel tool then just save yourself a headache and take it to someone.

 

[Kevin54]

He broke a tap. You can't drill a tap out. It will either have to be burnt out, or set up and take a carbide endmill to remove it. If it's burnt out, it will be done by an ELOX machine.

Normally if a tap breaks, especially a 1/4" size, there is a tooth broke and is now binding. And chances are you used a four flute tap.

Sometimes the tap will shatter completely in half, but I doubt it in your case. If you don't know someone with a mill, and that has carbide endmills to eat it up, then check around some job shops in your area to see if they can remove it. You can try a tap extractor, but good luck with that. Sometimes you can take a small punch and hammer, and hit the high side of the tap to try and back it out. It won't go forward.

If you get to the point that you exhaust all avenues, send it to me and I'll take it out for the cost of shipping it back to you. Over the years that I've worked in tool & Die, I have removed thousands of broken taps.

And don't use four flute taps, especially in a through hole. Always use a 2 flute spiral gun tap. Way less breakage.....Guaranteed!!!