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Broken drill bits remover


#1

Hello All!!

I just saw a product commercial on T.V.,for “Grabit” broken screw
remover.

It was made of hardened tool steel, and looked like the perfect
thing for removing broken drill bits from metal!!!

First, you cut/ burnish a cone shaped “seat”, and then the other end
has a cone shaped, double cut, bur-like grabbing tip…basically,
it bites into the broken drill, and then reverses it out of the
hole…?, Unfortunately, the “Grabit” appears to be for much larger
drills/ screws than we use for jewelry.

Does anyone know of a source for this type of thing for smaller
sized drills?

Best Regards,
Julie


#2
Does anyone know of a source for this type of thing for smaller
sized drills? 

You will find screw extractors at Industrial supply sites like
use-enco.com and mscdirect.com. These typically go down to Screw size
5-6 or M3. Other option is left hand carbide drill bits. Many times
drilling out a bit or screw will loosen/unscrew it.

Norman


#3

Micro Mega a Swiss based Dental products group used to market a kit
for removing broken instruments from root canals. If it or its
successor is available that might help.

Best of luck. Peter


#4

Thry’re called “EasyOuts”. Been around for years, but nothing small.
Usually used by mechanics. Alum still works best for small drill
bits. Just how did you plan to center-drill the broken drill bit?


#5
Does anyone know of a source for this type of thing for smaller
sized drills? 

The trouble with doing this with drill bits is that, unlike screw or
bolt heads, drills are hardened steel, often high speed steel. You
can’t just use a tool to cut that cone shape depression, or use a
toothed tool that grabs it like the grabit, or like traditional
removers of other brands that may require a hole drilled beforehand.
To remove drill bits you generally have to dissolve them. The
machinists doing this often need to remove steel or HSS drills from
things that are themselves made of steel, which is then a problem.
With jewelry, though, we’re usually removeing broken drills that are
stuck in precious metals, and these metals, fortunately, usually can
withstand being soaked in something that can easily dissolve the
drill bit without harming the jewelry metal. Most mild acids will do
fine. Ordinary pickle solution is a common and effective choice. Mix
it up new in order to avoid getting copper plating around the drill
hole. Once the bit is dissolved, the new small batch of pickle you
mixed to dissolve the bit can be saved for the next time, or just
added into your regular pickle. The dissolved steel will not cause
future problems or copper plating in other things. Another
traditional agent to remove broken drill bits is Alum. Works best
when boiling. You can get it in the grocery store in the pickling
spices section.

Peter


#6

Often the stuck drill-bit breaks again, because the metal has been
compacted and forged around the drill bit, when you try to remove it
by a reversing action. It is hard to believe that this tool will do
a good job for a.5 broken bit??? Mostly the drill breaks at the very
end, when you almost through silver or so and in that case you can
try to use another broken (softer) ball burr (.5mm) shaft as a punch
to drive it through (first annealing will help). When it stuck half
way I found that long annealing soften it just enough for drilling
out the stuck bit (not brilliant for the new drill, but it does
drill out). ‘Burrlife’, or similar will avoid the drill to clock up
in the first place.

Peter Deckers
New Zealand


#7

Hello all

There is a cleaning product here in New Zealand called Janola that
eats through drill bits in about an hour or so. I dont know whats in
it as I cant find the bottle right now but Im sure you can find out
on the internet and no doubt there is a similar product in most
countries. The drill bit basically turns to rusted mush which can be
ultrsoniced out and if some little pieces are still embedded a short
re-soak might be necessary. Make sure you get it all or else the
remaining steel will rust behind a diamond and make it appear brown.
Then you will have a hard job removing diamond to remove metal.

Thanks
Phil W


#8

Sodium bisulfate (alum) pickle works fine on steel in more in noble
metals and aluminum - works faster hot with occasional agitation.
When th bubbles slow down you are almost done or are done.

jesse


#9

Hello Peter,

Another traditional agent to remove broken drill bits is Alum.
Works best when boiling. You can get it in the grocery store in the
pickling spices section. 

Please help me understand. I was drilling out a sterling bead and
broke off the bit (of course!!). I put the bead in an alum solution -
that was a year ago. The water has evaporated and the alum has formed
nice crystals, but the bit is untouched. What is wrong??

The only thing I can think of is that the bit (I think it’s carbide)
is resistant to chemicals.

Suggestions?
Judy in Kansas


#10

Well one thing that’s wrong is that you need a solution for it to
rust so don’t let it dry out. You will need a strong enough solution
of alum to rust in real time, as I imagine a year is much too long
to wait for such a thing! A stronger solution and don’t let it
evaporate for starters.

Helen
UK


#11

Send it to the refiner, Tungsten Carbide is not soluble in anything
that I am familiar with. The Alum, pickel trick only works on steel
bits. Save the carbide bits for use on hardened steel or other
difficult to drill materials. Use only in a drill press with a
rigidly clamped workpiece and lots of lubrication and very high
speeds. They are very hard but also quite brittle and the slightest
wrong movement will break them.

James Binnion
@James_Binnion
James Binnion Metal Arts


360-756-6550


#12

Hi Judy,

For carbon or high speed steel bits, Alum works. It needs to be a
pretty much saturated solution, and boiling, as I noted. Had it been
a steel bit, 20 minutes in such a solution would have done it. Cold
and mixed to a weak solution might not work well, in part because the
alum isn’t such a strong agent, but also because, if cold, the bit
likely still has wax or oil from drilling coating it. That’s one
additional reason to use the solutions hot, since wax and oil get
removed more easily, allowing etching of the bit.

But carbide isn’t a steel, and as you’ve found, alum doesn’t touch
it. Sparex, or other sodium bisulphate pickle, though, seems to.
Newly mixed, pretty strong, and hot, is how I’ve used it with
carbide. It’s a bit slower than on steel bits, which get cleaned out
pretty quickly, but it seems to work. If I’m in a hurry, I’ll put the
hot pickle in a glass beaker with a loose cover and hang that in the
hot ultrasonic cleaner, which keeps the pickle hot, and also then
adds ultrasonic action to the recipe.

Carbide, though hard, isn’t my favorite for drill bits, precisely
because they break so easily. The keep their sharp edge, of course,
but broken, that’s of little use. I prefer high speed steel. Though
they dull more easily, they start out sharper, I think. Carbide is
nice for the harder to drill metals like titanium, or for pearls, or
other hard materials. But when I can, I still prefer High Speed
Steel. I’d rather have to resharpen a dull HSS bit than have to
bother with trying to extract the shards of a broken carbide one,
even if Pickle does eventually dissolve it…

Peter


#13
Sodium bisulfate (alum) pickle works fine on steel in more in
noble metals and aluminum - works faster hot with occasional
agitation. When th bubbles slow down you are almost done or are
done. 

Yes indeed. But sodium bisulphate is not Alum. Alum is hydrated
aluminum potassium sulfate. (thanks wikipedia). Sodum Bisulphate is
the same as Sparex or the ph-down spa chemicals. A sulphuric acid
salt, it’s a good deal stronger as a solvent for drill bits than is
alum.

Peter


#14

Thanks Peter for the explanation and solution to my problem.

I’ll do the hot Sparex thing. I now have a much better understanding
of bit selection. You’re the MAN!

Judy in Kansas


#15

Surprised that sodium bisulfate will attack carbide, I will file
that one away for future use, Thanks Peter

James Binnion
@James_Binnion
James Binnion Metal Arts


360-756-6550


#16
Surprised that sodium bisulfate will attack carbide, I will file
that one away for future use, Thanks Peter 

So was I. It was one of those surplus industrial drills. Short
little 1/8 inch shank with a tip more like a tiny milling cutter, but
a drill nevertheless, probably for circuit boards. I’d bought a box
of a bunch of them, resharpened industrial surplus or something from
Harbor Freight. The thinner ones would break at the mere suggestion
of abuse. It’s always possible they weren’t standard carbide, though
I don’t know exactly what that might be. Harder than HSS at any rate.
And wouldn’t you know it, I was dumb enough to be using them on
platinum, thinking they’d last longer or something. When one broke
off, and I couldn’t mechanically drive out the broken tip, I tried
the pickle as a last resort, and though slow, it worked. I can’t say
I’ve got lots of experience taking carbide bits out. Just that one.
But it did work that time. “Your mileage may vary…”

Peter


#17

It will depend on what the sintering binder is – Nickel binder will
corrode out the carbide won’t nor will chrome or cobalt.

jesse


#18

I too, was surprised at the idea of dissolving tungsten carbide,
until I looked at the actual chemistry. These drills are not pure
tungsten carbide, but a fine powder of tungsten carbide cemented or
welded together in a sintered mixture with cobalt. Even if the
tungsten carbide were insoluble, there is literature and patents
which suggest that the cobalt can be dissolved leaving behind a slush
of tungsten carbide particles. I have not tried this myself, but my
texts say cobalt is soluble in acids. There are two different
compounds of tungsten carbide, WC and W2C. I believe that most tools
use the insoluble WC form. W2C is slightly soluble in H2SO4 and
soluble in hot nitric acid - although I for one am not quite crazy
enough to do that without a fume hood.

Marlin


#19

Peter, Jim and any with odd interests:

In my professional life a surgical center was one component of my
practice. Beginning in about 1976 I used a tungsten carbide lathe
cutter insert (one of the one inch round ones that I found at Boeing
surplus) in surgery. It was sterilized along with all my goodies and
my assistant used it to form the tip of a new hypodermic needle into
a vicious little hook which I then used as a disposable surgical
instrument. The sterilization cycle was carried out at about 250 F.
in an atmosphere of alcohols, ketones, formaldehyde and about 9%
water. For some 35 years these sterilizers had no noticeable effect
on instruments made of 300, 440 and 770 series stainless, nor on
titanium or my diamond scalpels. HOWEVER, the cutting edges of the
carbide inserts simply disappeared after several months! The flat
surface was little affected remaining slick and hard and just right
for making hooks on needles.

I’ve never looked into the explanation, perhaps one of our metals
wizards can enlighten us.

Dr. Mac


#20
It will depend on what the sintering binder is -- Nickel binder
will corrode out the carbide won't nor will chrome or cobalt.

Thanks, Jesse, I’d not thought of the sintering binder. That makes a
whole lot of sense. So that means I was just lucky that the drill I
needed to remove was sintered with nickel. Any decent way to tell
what the binder is for a given piece of carbide?

Thanks,
Peter