type | IADC Code | Applicable formation | Main characteristics of the bit | Recommended parameters | |
Cutting structure | Normal WOB KN/mm(bit dia.) | Rotary Speed(rpm) | |||
TFJT447G | 447 | Soft with low compressive strength and high drillability,such as shale,clay,sandstone,soft limestone,salt bed and gypsolyte,etc. | Conical compacts in inner row,wedge compacs in outer row,with increase number of compact rows , and a row of trimmers is added between gage row and heel row. | 0.35-1.03 | 300-60 |
TFJT517G | 517 | Soft with low compressive srength and high drillability,such as shale,clay,sandstone and soft limestone.etc. | Large dia offset crested scoop compacts in inner row,wedge compacts in outer row. and a row of trimmers is added between gage row and heel row. | 0.35-1.05 | 300-60 |
TFJT537G | 537 | Medium soft with low compressive strength and harder abrasive stringers,such as hard shale,hard gypsolyte,soft limestone,sandstone,and dolomite with stringers,etc. | offsset crested scoop compacts in inner row,wedge compaces in outer row, inequable spaced compacts arrangement. and a row of trimmers is added between gage row and heel row. | 0.35-1.07 | 300-60 |
TFJT617G | 617 | Medium soft with high compressive strength and thick & hard strngers,such as hard shale,limestone,sandstone,and dolomite,etc. | Large dia offsset crested scoop compacts in inner row,wedge compaces in outer row, and inequable spaced compacts arrangement. and a row of trimmers is added between gage row and heel row. | 0.50-1.10 | 220-40 |
TFJT637G | 637 | Medium hard with high compressive strength and high abrasive ness,such as limestone ,dolomite,sandstone and chert,etc. | Large radius scoop compacts in inner row,spherical compacts in outer row, and a row of trimmers is added between gage row and heel row. | 0.50-1.20 | 220-40 |
