Increasing hole size in agate beads

Hi everyone

I have a design that requires the holes in agate beads (about 1.5cm
diameter), to have holes about 3.7, and it’s taking me forever (ie
about an hour) to drill through the existing holes, with a diamond
bur. Is there any magic technique I can use to speed this up, any
advice very happily received.

Best wishes from Tasmania, Australia
Anna M Williams

You should be using core drills rather than a burr. They contact
less material and so cut the hole faster. Although getting one
exactly 3.7 mm may not be possible.

These guys seem to have a very extensive catalog.

I use diamond core drill bits from THK on ebay. Teddy is located in
Hong Kong. Very reliable. The heat generated will be severe. A
constant trickle of water is required.

They wear out quickly=> get a bunch & watch your fingers when it
pushes thru!

Holler if you have any questions,
James
Digipod on Etsy

burrs from lasco

Mark Zirinsky
denver

Since there is already a hole in the bead, you can try a series of
ball burrs that are graduated, that should go faster.

Core drill would be hard to center.

Ball burr is graduates in size as it goes through. Start with one
just a bit larger, Have a good source of water, drill in a bit, pull
out, a little more, pull back out until half way, then go to other
side.

Thanks Eliot

I had a look through " it looks absolutely wonderful! But the sizes
are either too small or too large for my needs, but it did help me
understand a lot about the issues involved in cutting hard stone.
I’ll continue searching on the web, but I have ordered some cheaper
ones that are 4mm in size, so hopefully they will work.

Best wishes,
Anna

I have a design that requires the holes in agate beads (about 1.5cm
diameter), to have holes about 3.7, and it's taking me forever (ie
about an hour) to drill through the existing holes, with a diamond
bur. Is there any magic technique I can use to speed this up, any
advice very happily received.

Being that you already have a hole I think the core drill I’d the
wrong technique. Do what you are doing with the diamond burr but use
it in water. No fast way. Change the size of what is going through
them, that might be faster.