en
The bit is designed for drilling of extra hard abrasive rock formations, e.g. thick quartzite, extra hard siliceous shale, metabasalt of basalt group, granite-porphyry, massive porphyrite, corundum ore, nephrite and titanium-magnetite coherent rocks, and also pyriteous massive hornfels, most frequently found in gold, iron and granite mines.
Recommended drilling parameters for maximum efficiency of the bit: low and medium rotation speed (60-115 RPM) and axial load from 120 to 230 kN.
Rock strength range - from 55 000 to 66 000 PSI.
| Bit diameter, mm | 244.5 |
| Bit diameter, inch | 9 ⅝ |
| Bit designation, IADC | 822Z |
| Connection thread, API | 4 ½" FH |
| Bearing type | Air-cooled, on rolling bearings |
| Formation type | For extra hard abrasive formations |
| Rotation speed. RPM | 115-60 |
| Max. applicable load, kN | 120-230 |
| Weight, kg | 42.8 |
| Bearing/cooling type | Roller – Ball – Roller / Air cooling |
| Blow-through type | Side / center |
| Cutting structure | Tungsten carbide inserts |