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7 7/8″ MR845 Tricone Bit
IADC 845 · Φ200mm · 34kg · 4 1/2″ API
Cutting structure & formations
Gage rows: Ovoid. Inner rows: Ogive. For extremely hard formations with high compressive strength, typically magnetite quartzite, quartzite, granite.
ORIGINAL · EN Ovoid on gage, ogive on inner rows. Designed for extremely hard and abrasive formations with high compressive strengths such as magnetite quartzite, quartzite, granite.
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/Sealed Bearing
- WOB 39,380–63,000 lbs, rotary speed 50–80 rpm
Technical parameters
| Model | MR845 |
|---|---|
| IADC code | 845 |
| Diameter | 7 7/8″ / Φ200mm |
| Thread | 4 1/2″ API |
| Weight | 34 kg |
| Bearing type | Roller-Ball-Roller-Thrust Button/Sealed Bearing |
| Circulation | Jet Air |
| Inner row teeth | Ogive |
| Gage row teeth | Ovoid |
| Gage bevel protection | Round |
Operating suggestions
Actual parameters must be set per application
| Weight on bit | 39,380–63,000 lbs |
|---|---|
| Rotary speed | 50–80 rpm |
| Air back pressure | 0.2–0.4 MPa |
| Formation strength | 58,000–70,000 Psi |
