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7 7/8″ MR412 Tricone Bit
IADC 412 · Φ200mm · 34kg · 4 1/2″ API
Cutting structure & formations
Gage rows: Conical. Inner rows: Conical. For hard formations with high compressive strength.
ORIGINAL · EN Chisel on gage, conical on inner rows. Designed for very soft formations with low compressive strengths and high drillability such as shale, soft limestone, sandstone, conglomerate, soft dolomite and coal ore.
Shirttail protection
Hardmetal on lug; Wear resistant carbide on shirttail lip and lug.
ORIGINAL · EN Hardmetal on lug; Wear resistant carbide on shirttail lip and lug.
- Diameter 7 7/8″ / Φ200 mm, weight 34 kg
- Connection 4 1/2″ API, bearing Roller-Ball-Roller-Thrust Button/Open Bearing
- WOB 7,880–15,750 lbs, rotary speed 90–120 rpm
Technical parameters
| Model | MR412 |
|---|---|
| IADC code | 412 |
| Diameter | 7 7/8″ / Φ200mm |
| Thread | 4 1/2″ API |
| Weight | 34 kg |
| Bearing type | Roller-Ball-Roller-Thrust Button/Open Bearing |
| Circulation | Jet Air |
| Inner row teeth | Conical |
| Gage row teeth | Chisel |
| Gage bevel protection | Round |
Operating suggestions
Actual parameters must be set per application
| Weight on bit | 7,880–15,750 lbs |
|---|---|
| Rotary speed | 90–120 rpm |
| Air back pressure | 0.2–0.4 MPa |
| Formation strength | 4,000–7,000 Psi |
