Sintered Drill
A sintered diamond drill bit. Smaller drills are 120 grit and the larger 2.3mm drill is 80 grit. Then there are also enlarging drills leaving a finish of 325 (2.3 or 2.9mm) or 600 (2.9 or 3.3mm) grit to help in pre-polishing the final hole.
Diameters in mm. 1.0, 1.2, 1.6, 2.3, 2.9, 3.3
