Removing a broken center drill tip.

[tvoght]

Today I was center drilling a piece in the lathe. As seems to
happen far too often with me, the center drill tip broke off in the work.
I swore out loud, but I had some hope. Just a couple of days ago I had read a
tip in a book about how to remove the broken tip from the workpiece.

I decided to try the idea, and it worked!

The remainder of the broken drill was modified with a Dremel abrasive cutoff
disk. A center section as wide as the broken off tip was ground away leaving
cutting edges only in the area surrounding the tip (see the photo).

The idea is that the modified drill will cut away the material around the
broken tip without touching the tip itself. When enough of the surrounding
material is removed, the broken tip simply falls out.

I hope the photo is clear enough.



Again, I take no credit for the idea, I saw it in a book.

--Tim

[zeeprogrammer]

Cool! I've had that happen so this is helpful. Thanks!

[sasquatch]

Thanks, good tip to remember!!

[Stilldrillin]

Great tip Tim!

I don't use centre drills, unless I need a locating hole, for a centre.......

But, for drill starting. I have had the same 3mm dia spotting drill, for several years. Still good as new! 

David D

[mklotz]

HF, among others, sells small diamond core drills for, nominally, drilling glass and ceramics.

I've often wondered whether one of those could be used to "undermine" a broken drill tip so it, and its surrounding material, could be knocked loose with a small chisel.  They're cheap; it's worth a try.  If it doesn't work out you could always use it to make some hideous, artsy-fartsy lamp out of a milk bottle or whatever.

[Don1966]

Thanks for the tip Tim I have broken a few myself.

Don

[Jo]

  Nice trick.

Also worth rapping the piece of metal on the bench, if you can get the swarf out from around the tip, often as not it will come free. If it is a through hole then try drilling from the other side  .

I also keep some of my broken  1mm drills for use as "swarf picks", you can often get these down the flutes of the broken tip, give it a twist and free up the swarf/drill tip.

Jo