Glass Drilling And Core Drills
What This Process Needs To Solve
Drilling is the operation that fails last and worst. An edge can be re-polished; a hole that breaks out at the exit cannot be recovered, and on laminated or tempered stock the whole panel is scrap. Glass core drills are therefore specified around breakout, not around penetration rate.
We supply grit from 60# to 325# for sintered and electroplated core drills, with nickel-coated grades for electroplated barrels.
Why grit is set by glass thickness, not by hole size
A thin pane tolerates a coarse grit because there is little material under the bit and the load per particle stays low. The same grit on 12 mm float releases its energy at the exit and spalls the far face. The working rule is the inverse of what most operators expect: the thicker the glass, the finer the grit and the slower the feed.
Sintered bodies or electroplated barrels
Sintered core drills run one diameter all shift on a production line; electroplated barrels are used where the diameter changes often and cost per hole matters more than tool life. The two take different diamond. Sintered bodies need blocky, high-strength grit that survives the sintering cycle. Electroplated barrels need strictly graded grit, because a single oversize particle lifts the plating and the barrel sheds that whole patch.
What we hold on the batch
Magnetic content and non-diamond residue are reported per lot. On glass both present as breakout at the exit edge rather than as wear, which makes them difficult to trace back to the powder once the panel is scrapped.
Where It Goes Wrong
- Breakout on the exit face. Grit too coarse for the thickness, or feed too fast at breakthrough.
- Barrel sheds grit after a few holes. Plating thickness, or one oversize particle lifting the layer.
- Hole diameter drifts over the run. Grit too fine for the bond, so the matrix wears before the diamond does.
- Overheating at depth. Coolant starvation, which presents as a powder failure but is not one.
Recommended Grit By Drill Type
Core drills are specified by body type and glass thickness. The thicker the glass, the finer the grit.
| Drill type | Recommended grade | Grit / size | Why this grade |
|---|---|---|---|
| Sintered core drillsFixed diameter, production line | |||
| Sintered body, thin glass | MBD series | 80# – 170# | Blocky grit survives sintering and holds the matrix |
| Sintered body, thick glass | MBD series, finer cut | 170# – 270# | Finer grit releases less energy at the exit face |
| Electroplated barrelsDiameter changes often | |||
| Electroplated barrel | RVD / RVG, Ni coated | 100# – 230# | Strict grading keeps the plating intact; Ni keys into the bond |
| Electroplated barrel, fine hole | RVD / RVG, Ni coated | 230# – 325# | Finer grit limits breakout on small diameters |
Factory Direct Since 1990
Zhecheng Hongxiang Superhard Material Co., Ltd. is an integrated manufacturer and exporter of synthetic diamond powders since 1990, located in the Diamond Capital of China.
- Own manufacturing base in Zhengzhou, Henan — powder, coating and grading on one site.
- In-house particle size and SEM inspection on every batch before packing.
- Export packing with neutral or custom label, plus sample quantities for process trials.
What To Include
Describe your workpiece, process and target result. We will match the diamond grade from the existing product range.