I searched for months looking for a Braille drill bit that will provide the perfect friction fit for installing Braille spheres in Corian signs.
Here it is:
http://brailleballs.com/
Item CNCBRL
I had to edit the link above because it changed.
The bit I am using can be found on Amazon or any number of other web sites.
M.A.Ford
EDP 32341
Twister Miniature Drill
1.55 MM solid carbide spiral drill
30206100
1/8” Solid Carbide shank with a spiral bit. Specially used for CNC Routers.
Price: $16.00 each
They sent me a bit to test just to make sure the fit is perfect. I tried the bit this afternoon and the spheres fit perfectly, just enough of a friction fit so the spheres won't fall out.
.