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Enlarging drill holes in stone beads


#1

Hi folks,

I’m not sure what the accepted wisdom is when enlarging drill holes
in stone beads, but I found something that worked well for me today.
I decided to drill larger holes through some Chrysocholla beads I
have, in order to thread them onto thicker silver wire (to make
silver links). The original holes would only accommodate 0.8mm thick
wire, which is still a little bendy even if you twist to harden it -
and I feel that more substantial wire equals nicer quality too. I
started out using an HSS steel drill bit but even though a soft
stone, it was dulling my drill bit very quickly and I only had two
drill bits of that size.

To lengthen the life of my drill bits I used a tapered, diamond
covered burr to enlarge both ends of the hole and prevent breakout
then went back to my drill bits.

After a long introduction I’ll get to the point! As my drill bit was
so dull anyway, I thought there was nothing to lose by trying to
sharpen it, so having read a couple of articles about sharpening the
cutting faces of drill bits I held the bit lightly against a cheap,
wide diamond coated burr at an angle, while the bit span in the
flexshaft handpiece. I suppose a flat faced diamond coated file
would have been better, but it put enough of an edge on the cutting
faces to continue cutting through my beads. After every few beads, I
repeated the process and restored the cutting edges. I managed to do
about a hundred beads with one drill bit.

There are probably better products for doing that, but I used what I
had and the drill bits would only have been thrown away anyway.

Helen Hill
http://www.hillsgems.co.uk


#2

Hello Helen,

Ask your dentist to save all of his used diamond bits for you. They
use all kinds of thin pointy shapes that would be very handy for
enlarging holes in stone beads. They also have lots of life left,
stones don’t mind if it takes a little longer to cut, dentist’s
customers prefer the bits are replaced as soon as the fresh diamond
shows any signs of wear.

Tony.
www.OpalsInTheBag.com