en
The bit is designed for drilling of soft abrasive rock formations, e.g. chalk, marl, dolomite, marlous limestone and sandstone with aired out cement, volcanic tuff, medium and hard coal, aleurolite and apatite-nepheline ore, coarse-grained marble, quartzeous and micaceous shale, phosphorite and conglomerate of sedimentary rocks, overburden of coal seams, also found in shale mines.
Recommended drilling parameters for maximum efficiency of the bit: low and medium rotation speed (60-115 RPM) and axial load from 80 to 190 kN.
Rock strength range – from 2 000 to 6 000 PSI.
| Bit diameter, mm | 244.5 |
| Bit diameter, inch | 9 ⅝ |
| Bit designation, IADC | 422X |
| Connection thread, API | 4 ½" FH |
| Bearing type | Air-cooled, on rolling bearings |
| Formation type | For soft abrasive formations |
| Rotation speed. RPM | 115-60 |
| Max. applicable load, kN | 80-190 |
| Weight, kg | 42.0 |
| Bearing/cooling type | Roller – Ball – Roller / Air cooling |
| Blow-through type | Side / center |
| Cutting structure | Tungsten carbide inserts |