Oilfield Drill Collar
The Drill Collar is made from AISI 4145H alloy steel, and completely meets the requirement of API Spec 7-1 and SY/T5144 Standard. It is the round pipe with smooth surface and thick wall, and the both ends are machined screw thread for connection. It is mainly used between the drill head and the drill pipe, so that it can make the drill head work reposefully and keep right trace by providing the pressure and weight for drill head.
| OD | Cutting | Lead±25.4 |
| mm | in | A(mm) | B(mm) | mm |
| 86 | 3 3/8 | 3.5±0.79 | | 679 |
| 98.4 | 3 7/8 | 4.0±0.79 | | 914 |
| 101.6～111.1 | 4～4 1/8 | 4.8±0.79 | | 914 |
| 114.3～130.2 | 4 1/2～5 1/8 | 5.6±0.79 | | 965 |
| 133.4～146.1 | 5 1/4～5 3/4 | 6.4±0.79 | | 1067 |
| 149.2～161.9 | 5 7/8～6 3/8 | 7.1±1.59 | | 1067 |
| 165.1～177.8 | 6 1/2～7 | 7.9±1.59 | | 1168 |
| 181.0～200.0 | 7 1/8～7 7/8 | 8.7±1.59 | 5.6±0.79 | 1626 |
| 203.2～225.4 | 8～8 7/8 | 9.5±1.59 | 6.4±0.79 | 1727 |
| 228.6～250.8 | 9～9 7/8 | 10.3±2.37 | 7 |
