Micro forstner bit or bur?

Jewelry Discussion
1

Does anyone know of such a thing as tiny perimeter cutting burs or
bits? Like micro forstner bits? If so, could you please point me to a
source?

Thanks so much!
Mary Barker

2

Mary,

Try looking for inverted cone burrs. They range in size from about
1/2mm up to more than 2mm. Available from Otto Frei, Rio and other
tool suppliers.

Roger

3 
Does anyone know of such a thing as tiny perimeter cutting burs or
bits? Like micro forstner bits? If so, could you please point me
to a source?

Perhaps you need core drills, like these:
http://www.lopacki.com/coredrills/

Al Balmer
Pine City, NY

4

It would depend on the intended purpose and size of this bur.

The are wheel burs which can be ground down to be a simple end
cutter, or there are simple end cutters. Neither of which is going
to be real controllable without a preformed hole as a start. Ex, you
want a 1.8mm hole…start with a ball bur go to 1.7mm, then use an
endcutter to true up the size and profile. Because wheel burs cut on
the edge as well as the face, they can wander if you don’t grind the
edge off. By grinding you can also make to whatever exact size you
need

Pearl drills look like carpenters spade bits so that might be
something for you, self centering but its going to leave a small
dimple in the middle of your finished hole.