A guy I work with busted off a #43 drill (.089) into an custom part (1018 cold rolled steel) we are making. This happened on the last operation on a labor intensive part. The bit is broken off about 1/4 inch below the surface of the part. We are trying to extract this bit so we can re-drill the hole and hopefully salvage the part. Any ideas on how to do this. We would prefer not to drill it out with a smaller bit but if that's what needs to be done, I guess we have no choice. Thanks guys.

I would toss it in the EDM machine and burn it out.

DareBee, thanks for the reply. Great suggestion but we don't have access to an EDM and can't send it out because we are crunched for time, need it out the door tomorrow for plating.

CAN YOU DRILL THRU FROM THE OTHER SIDE?
LIKE DRILL A SMALLER HOLE AND PUSH THE BROKEN DRILL OUT WITH A DRILL BLANK.
IF NOT YOU WILL HAVE TO FIND SOMEONE THAT FIXS BROKEN TAPS... SHOULD ONLY TAKE AN HOUR OF SO TO FIX, IF YOU FIND THE RIGHT GUY!

send it out to a hole popper,cheap and fast

dont even try to drill it out,you will scrap the part,the drill always runs off and into the sidewall

Purchase a straight 2 flute solid carbide end mill (or borrow one from another shop),and peck out the broken drill. Peck agaist the quill stop in .001 increments with lots of cutting fluid.
I had the same problem 2 weeks ago with a 6-32 tap in 1020. I used the endmill, and after about 15 minutes had the broken tap (HSS) reduced to powder.

good luck

An idea: counterbore the surface to about 1/4" diameter down til you get to the drill remnant. If you have cnc, you could even interpolate around the drill to remove the base metal until you have a 1/16" of the drill sticking up. Then using a UTP65 welding rod (or equivalent, all rod manufacturers have one of these specialty high alloy rods) spot a little ball on top of the drill remnant. Pause and repeat until you've built the remnant up another 1/8" then place a small nut over this tit and weld it on. Then, gingerly try to rotate the drill and back it out of the hole.

If you really mess it up, you can always drill and tap the location for a 1/4" bolt, which you can apply Loctite to, and then screw that bolt in til it bottoms and jams good in the thread, cut the top off and file the surface smooth. Then redo the proper tapped hole in the center of the stud.

If you really mess it up, you can always drill and tap the location for a 1/4" bolt, which you can apply Loctite to, and then screw that bolt in til it bottoms and jams good in the thread, cut the top off and file the surface smooth. Then redo the proper tapped hole in the center of the stud.


Ah the old all-thread trick. Sandvik makes solid carbide drill sets for removing taps that break, doesn't do you any good now, but they work good for anytime they're needed in the future. (knock on wood)

Sorry about the delay guys. Just wanted to update you on what happened. We got permission from the customer to oversize that hole which allowed us to drill the hole from the other side and basically punch it out. We then redrilled the hole slightly bigger.