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Reaming gemstone beads

I have a diamond coated bead reamer (from Rio Grande, a Eurotool
product) and am wondering if it works on The directions
say glass, stones, ceramic, metal. Does anyone have any experience
with this? Thanks! Iris in San Francisco

Hello Iris, your bead reamer(s) coated with diamonds are excellent
for any material even diamond beads. I picked up a really cheap set
on Ebay and it is diamond coated. I’ve used it on ruby and sapphire
beads with great success. You’ve got the right tools for the job.

Jon in Montreal

It absolutely works on (most) :slight_smile:

Keep the drill bit and the stone bead wet–I use an old tupperware
bowl filled with water and ream the bead under the water. If you
dry-ream the beads, you run more risk of shattering the stone and
also will wear the diamond coating off the bit much faster.

Sometimes the bead will still shatter, but most can be safely
reamed–it’s just a tedious process. Unless my design really needs
a heavier wire, I’ll usually try to work with a smaller gauge wire
to avoid reaming.

Also, some beads are just too big to be reamed out successfully,
since the bits are tapered. But most gem beads can be made to fit a
larger wire (or stringing medium) with a gentle hand and some


I use a 0.75mm or 0.8mm diamond-coated drill bit in a small
hand-held hobby-drill. But, it must be done under water. I anchor the
bead(s) firmly in Blu-tack then cover them with water in a shallow
dish. The drills are not tapered, so make a clean, straight-sided
hole. The trick is to apply very little pressure (or the drill may
snap) and to lift it frequently to allow water into the hole to wash
away the dust and relubricate. This works for every stone I tried,
including pearls and quartzes. If the drill ceases to cut
efficiently, it needs replacing. This way is very much quicker than
reaming and a great deal less effort is needed. I have a permanently
dislocated thumb, so reaming was not only time-consuming and tedious
but also very painful.


    I use a 0.75mm or 0.8mm diamond-coated drill bit in a small
hand-held hobby-drill. 

Hi Pat, Can you tell me where you purchase your diamond coated drill
bits? I have never seen these and would love to try it out on some
problematic beads I have.

Wired Contemporary Jewelry

Hi Carrie,

I get them from two places, and The latter are a lot cheaper, but have
shafts the same diameter as the bit itself, so you do need a drill
chuck that will cope with them. Fortunately mine does, but I also
have an Archimedian Hand Drill (from Cooksons) that accommodates them
which is obviously slower but it still beats reaming!