Drag bits are suitable for the drilling of some softer layers of rock formations, such as carbonatite, limestone, chalks, clay rocks, siltstone, sandstone and so on. Compared with the common drilling bits, the drilling result of the drag bits is superior.
Thread Type No. | Bit diameter | Thread | |
mm | in | ||
NC | 65 | 2-7/8 | 23 |
API REG | 77 | 3-3/4 | 2-3/8 |
API REG | 102 | 4-3/4 | 2-3/8 |
API REG | 113 | 4-7/16 | 2-3/8 |
API REG | 127 | 5 | 2-3/8 |
API REG | 133 | 5-1/4 | 3-1/2 |
API REG | 152 | 6 | 3-1/2 |
API REG | 177 | 7 | 4-1/2 |
API REG | 203 | 8 | 4-1/2 |
API REG | 228 | 9 | 5-1/2 |
API REG | 254 | 10 | 6-5/8 |