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Snapped off tap. Suggestions for removal?

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C

Cutlass

Jedi Warrior
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When cleaning out the threaded tube welded to the front of the frame, where the towing bars are bolted, I snapped off a 3/8 inch tap. It's pretty well lodged in, but definitely not cross threaded. None is sticking out. Any ideas for removal?
 
Ouch ! I hate when that happens. The only thing I could think of is to try to drill a hole into the remaining piece and then use an easy out. Since it is tool steel, it will not be easy to drill a hole into ! I am certain others will respond with something that may be easier to do.
 
If it is broken off even, ( not too far below the hole ),
try hammering into the piece at a slight angle with a good center punch. You may be able to break the piece loose and then unscrew it using the center punch.
 
One more option; Find a drill bit that just fits inside of the hole. Use one of the other holes as the " gauge ".
Start drilling slowly at 1st to make certain that you are not drilling at an angle. Drill out most of the material of the broken off piece. The thin remaining piece of the tap can be bent inward away from the threads and pulled out of the hole. I have done this with success with broken off bolts, never tried it on tool steel but it should work if you can start the drill relatively straight.
 
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Try a tap extractor...
/ubbthreads/images/graemlins/england.gif
https://www.newmantools.com/walton/extrtap.htm

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I have found that they rarely work.

A better idea is to use a solid carbide drill bit (harder than the tap); left hand, if you can find one. A left hand drill bit (in a reversible drill motor) makes an xlnt "easy-out" in that the heat generated and reverse direction will often dislodge a broken bolt (or tap) once the bit digs in.
 
Got it out! It had broken off just below the surface. I used snap ring pliers, inserting the two tips into two of the four flute holes. Carefully turning worked. Luckily I was just chasing existing threads of paint before assembly. Thanks for the ideas. I'll use them next time the pliers don't work.
 
You can order left-hand drill bits from Northern Tool online. However, normal drill bits won't touch a tap and I don't think you'll find carbide left-hand bits anywhere.

The only time I've seen tap extractors work is when the tap broke because someone leaned sideways on the tap while threading the hole. If the tap breaks under pure torsion the extractors won't budge them.

Since this is a frame, the industrial way of removing the tap using a sinker EDM won't work. Frames are just too big. However, if you have a high-speed die grinder (not Dremel... an honest to God pneumatic die grinder) then you can use a carbide burr to grind out the broken tap. Common burrs have 1/4" shank diameter. You're best choice would be a conical solid carbide burr that doesn't exceed 1/4" diameter. You have to patiently advance the burr into the broken tap and worry it out of the hole.

Whatever you try, don't let anyone tell you to try and weld something to the broken off part. Taps are already brittle and the heat of welding will only make that worse.

EDIT: Darn... I posted 1 minute too late to be of any help!
 
Yep DK Randi wiped us out I didn't even get to post. But :I agree: you not going to drill into a tap /ubbthreads/images/graemlins/nonod.gif---Keoke- /ubbthreads/images/graemlins/laugh.gif
 
Maybe China made cheap tap methinks.---Keoke- /ubbthreads/images/graemlins/grin.gif
 
How did I snap it off? It's an embarrasing secret. Probably a cheap tap, too. Lesson learned. For what it's worth, this literally was the last hole in the chassis needing chasing.
 
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Maybe China made cheap tap methinks.---Keoke- /ubbthreads/images/graemlins/grin.gif

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Never, ever scrimp on a tap! A cheap (as in broken) tap can cost far more in the long run than you'd ever spend on a single tap.

Cheap taps = false economy.
 
To add to Randy's comments... don't use a dull tap either. You can check a tap by dragging its teeth on your fingernail. If it doesn't start to scratch your nail with minimal effort... use it with caution... or not at all.
 
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