Broken (drill) Tap- need advice!

[Dkevdog]

Installing some lighting on one of our trailers today and I managed to break an 8/32 tap in the damn hole. I can't get the broken tap out, and I've eaten two titanium bits apart trying to chase the hole... ... I really need the location that was drilled, moving it over is only a last resort. Any ideas??



Thanks!

Kev

 

[Jim Fulmer]

Kevin If it's were you can do this it might work as I have been told, take a torch and get the tap red hot, it's suppose to take the temper out of it. Keep in mind this is only from the horses mouth.



Jim

 

[illflem]

This is the way I do it, but you need an arc welder. Use a small rod, preferably a cutting type, crank the amps up and zap the rod to the broken tap, it will get red hot in a second. When the tap cools you can hit it with a punch and it will break into a million pieces (well maybe not that many but enough). This can be done with hardly heating the surrounding area and burning off paint etc like a torch will. Drilling a tap will get you nowhere. When tapping small holes it's very important that the tap is started straight or it will most always break. An easy way to get started straight if the metal is thick enough is to drill a slightly larger hole an 1/8" or so into the correct sized hole.

 

[M Barnett]

Give Jims idea a try and let it cool slowly. The reason you can't drill it out is because taps are hardened. It would take at least a cobalt drill to cut it. If you can't get it out, this would work. Blow through the tap with a cutting torch. Grind both sides of the metal to remove slag. Clamp a small plate on the backside of your hole and then weld the hole full from the front and start over.

M Barnett

 

[barryg41]

Dkevdog, back when I was a millwright, we use to use a punch to break up the tap. It was a pain in the butt. But if you want to use the same hole, you gotta do what you gotta do.



If it is a clear hole (no bottom) you might be able to push it through. If it is a dead hole, you might be able to break it apart and blow the pieces out with air.



I hate it! I HATE IT! When I break a tap in the hole.

 

[LSMITH]

Use a semi-automatic center punch (the kind you push on till they snap) to shatter the tap, then re-tap as normal. If you cannot shatter the tap then drive it out with a normal punch and tap to 10-32, this is likely your best bet for long term use anyway.

 

[DRR-24V]

Gunsmiths Nightmare !

Dkevdog,

If the tap is carbon steel you can usually shatter it with repeated punches with a spring loaded center punch. If its high speed steel you will have to heat it to soften it like Illflem said, or use a drop of Nitric acid on it and it will boil away the tap and not hurt the surrounding soft steel.

 

[Dkevdog]

What a PAIN in de A**!!!!!! I'm not sure of the material of the tap, I'll try any break it out with a punch first, its in 3/16 steel box tube and no way to get to the back/inside. If all that fails I've got a welder buddy who should be able to do the heat trick. Thanks guys!



Kev

 

[mikel]

Once I broke a tap off in the head of an old 280z and used a masonry bit to drill it out. It was slow and ruined the masonry bit, but it did drill the tap out.



Sounds like you have alot of ideas to try, let us know what works for future refrence.



Good luck,

Mike

 

[Joseph Donnelly]

A carbide bur in a Dremel will grind it out.

 

[Dkevdog]

Well thanks for all the tips and suggestions . As it turned out I was able to use a center punch and knock it out. It ruined the hole for any possible use by 8/32, but I think I can file the polycarbonate on the light (around the hole) and install a 10/32, as it will not fit now. I'm just glad I didn't have to resort to using a torch or welder!! !!



Thanks again to all!

Kev

 

[barryg41]

Glad everything worked out for ya, Kev!

 

[Doc Tinker]

I've done what illflem suggested with taps they break in cast iron, the weld doesn't adhere well to the cast iron, but it sticks to the tap.



If the trailer has nice paint on it and you don't want to make a mess of it, try using a punch to drive it through, then drill the hole larger and use a nutsert.



Taps are pretty brittle and I've been able to break them up with a pin punch, like barryg41 mentioned.



Doc

 

[Evan A. Beck]

OTC tools makes a set of tap extractors... I have them, and they are slick. They use a 4-prong bit that slides down the sides of the tap, and then you can just back the thing out.

 

[DRR-24V]

Evan-How About 2&3 Flute?

Do they make them for 2 and 3 flute taps. ?

 

[illflem]

When I worked more with heavy equipment an even worse problem than broken taps was large broken bolts and studs. Drilling and using an eze-out usually just resulted in a broken eze-out, sometimes drilling and retapping was out of the question. The last resort was laser stud removal, available in most large cities. Used to cost me $50 per bolt in the field and $10 if I brought it in. There is a last resort.

 

[DRR-24V]

Illflem- Is That Like EDM?

I have had to take stuff to have an EDM take it out and that little 4x48 tap costs $40 to remove. Kind of eats up all your profit.

 

[LarryB]

Originally posted by illflem

There is a last resort.

Yup, and here it is!

#ad

 

[RBrunson]

Broken bolts

A company in the Northwest called X-ARGON makes a welding rod called Extract a Loy. Put a nut over the hole and insert the welding rod down the hole and start the arc on the broken bolt. Letting the rod melt as you back out of the hole, you are filling the hole with molten metal attached to the bolt.



As you get to the nut, fill the nut with metal. You can now use a impact wrench and socket on the nut. Everything is hot and it will come out everytime, provided that you did a good job of attaching to the broken bolt. nine times out of ten the weld will not break, I have seen it done and it works.



The flux protects the walls of the hole so the molten metal will not adhear to it. Works really good on heavy equipment where big $$$$ are involved.

 

[Evan A. Beck]

Not sure DBR, I'll check it out.