Drilling methods for all hole depths
| Type | Depth Ratio | Diameter | Tolerance |
|---|---|---|---|
| Twist HSS | 3xD | 1-30mm | H7-H9 |
| Twist Carbide | 5xD | 1-20mm | H6-H8 |
| Indexable Drill | 3xD | 12-60mm | H8-H10 |
| Gun Drill | 100xD | 2-30mm | H6-H7 |
Deep holes (>5xD): peck cycle. Coolant-through drills above 3xD. Gun drill: 60-100 bar coolant.