en
The bit is designed for drilling of medium-soft abrasive rock formations, e.g. coarse grained mineralized marble, sandstone with clay-sericitic porous carbonate cement, quartzeous, micaceous and hard carbonaceous shale, phosphorite with phosphate cement, siderite and serpentinite, most frequently found in coal and shale mines.
Recommended drilling parameters for maximum efficiency of the bit: low and medium rotation speed (60-115 RPM) and axial load from 30 to 120 kN.
Rock strength range - from 6 000 to 24 000 PSI.
| Bit diameter, mm | 171.4 |
| Bit diameter, inch | 6 ¾ |
| Bit designation, IADC | 522X |
| Connection thread, API | 3 ½" REG |
| Bearing type | Air-cooled, on rolling bearings |
| Formation type | For medium-soft abrasive formations |
| Rotation speed. RPM | 115-60 |
| Max. applicable load, kN | 30-120 |
| Weight, kg | 18.7 |
| Bearing/cooling type | Roller – Ball – Roller / Air cooling |
| Blow-through type | Side / center |
| Cutting structure | Tungsten carbide inserts |