Replacing broken off ivory bead

[Stan Hillis]

How is the safest and best way to remove the threaded portion of an old ivory bead that has been broken off leaving only the threaded shank in the hole in the rib? My plan is, unless I hear of a better way, to carefully drill out the remaining part with a drill slightly undersized to the threads, then carefully pick out the remains with dental picks.

If there is a better way I would very much like to hear it before I undertake this job.

Thanks, SRH

[David Noble]

First, are you sure it was threaded in and not a taper fit?
If it is indeed threaded, use a machinist’s small “easy out”.
Drill the smallest hole that will allow the easy out to start in,
Then tap it in a tad, just enough for it to get a bite and use a tap wrench to turn it out counter clockwise.

[chris dawe]

You'll have no trouble drilling it out as you described, I've done it hundreds of times ,just take your time

[Stan Hillis]

Pretty sure this one is threaded, David. It's on a Sarasqueta. Having done similar jobs on steel studs or bolts that have broken off flush with the surface I am home schooled in the process, and the importance of centering the drill for the pilot hole. Hadn't considered using a tiny Eezy-out, but that's something to consider. Didn't actually know they were available that tiny. I'll look into it.

Thanks for the re-assurance, Chris. I'm seriously considering investing in a high quality set of left hand drill bits, just for this purpose. Unless the threads are corroded badly (obviously not the case here), I would think a left hand bit might grab just enough to bring it out by itself.

[chris dawe]

Nah,you can drill it close to size and it'll likely fall out or you can pick it out with an small awl or needle...it's a little brittle and easy to drill just be careful...if you could mount it safely in a press it'd be easier, I just took out a couple two weeks ago

[B. Dudley]

Most all are tapered press fit. Either way, just drill it out. Make sure you start out centered and increase drill size as you go. It will eventually pop out. Or once you get it thin enough you can just collapse the collar in on itself and pull it out.

[Stan Hillis]

Done that numerous times with sheared steel studs/bolts. Nice to know it will work the same with ivory (on a smaller scale ).

Thanks all.

[ArtS]

Should be easy to drill out. However, don't discount the left hand drills. I once had a starter mounting bolt snap off flush in a boat motor in a really awkard place. I could get to it to drill it using a mirror laying in the bilge, but there wasn't enough to get a swing to drive in and EZout. I ordered a short left hand drill bit, used the EZout hole as a pilot and started the bit. It came out with no effort. This of course is an entirely different size range. but te concept is very under rated I think. My theory was that the heat generated by the bit may have in some way may have been a contributor.

[Paul Golston]

I have had to drill out small screws out in the field doing service work. left hand drill bits are a must. EZouts are limited in the smaller sizes. I ditto ArtS theory , the heat and the bite of the drill bit will spin that problem away !

[chris dawe]

6Yeah,it's not a metal screw,Brian and myself have taken out quite a few between us ...no left hand anything or ez out needed, it's ivory sn soft as say oak,easily drilled easily removed that's why it broke in the first place