7 7/8″ MR545 牙轮钻头

齿型结构与适用地层

外排锥形齿、内排锥形齿。适用于中软地层（低抗压强度），常见岩性：页岩、软石灰岩、夹层白云岩、煤层。

ORIGINAL · ENConical on gage, conical on inner rows. Designed for medium-soft formations with low compressive strengths such as shale, soft limestone, dolomite with interlayers and coal ore.

保径保护

掌背镶硬质合金；保径唇口与掌背加焊耐磨碳化钨。

ORIGINAL · ENHardmetal on lug; Wear resistant carbide on shirttail lip and lug.

• 直径 7 7/8″ / Φ200mm，重 34kg
• 接头 4 1/2″ API，轴承 Roller-Ball-Roller-Thrust Button/Sealed Bearing
• 推荐钻压 15,750–39,380 lbs，转速 80–110 rpm