The coal bits mainly used in coal and mine drilling.We can do different measures according to customer's requirements or drawing
type one
| Colliery Tools | Main Standard(mm) | |||
| D | H | L | M | |
| 27 | 44 | 17 | M14×1.5 | |
| 27 | 54 | 17 | M12×1.75 | |
| Thread | 28 | 54 | 20 | M12×1.75 |
| joint | 29 | 52 | 18 | M14×1.5 |
| 30 | 50 | 18 | M14×1.5 | |
| 32 | 52 | 22 | M14×1.5 | |
| 32 | 56 | 22 | M12×1.75 |
type 2
| Colliery Tools | Main Standard(mm) | |
| D | M | |
| Thread Joint | 38 | 12 |
| 40 | 12 | |
| 42 | 12 |