Bit type | IADC Code | Applicable formation | Main characteristics of the bit | Recommended parameters | |
Cutting structure | Normal WOB KN/mm(bit dia.) | Rotary Speed(rpm) | |||
TH126 | 126 | Soft with low compressive strength and high (clay,mudstone,salt,loose sand,soft limestone,etc.) | bigger teeth with teeth space less than TH116,hardfacing on both flanks and outer face.Carbide insert on TH127 heel row and gage for special gage protection. | 0.351.00 | 15070 |
TH127 | 127 | ||||
TH136 | 136 | Soft to medium soft with low compresive strength or soft with harder streaks(shale,mudstone, soft limestone,sandstone,etc) | Shorter teeth with less teeth space,hardfacing on all teeth faces and gage .Carbide insert on TH137 heel row and gage for gage protection. | 0.351.05 | 12060 |
TH137 | 137 | ||||
TH216 | 216 | Medium hard with higher compressive strength and hard streaks(hard shale, sandstone,limestone,etc.) | Less teeth and teeth space,gage protection by using T shape teeth on the heel row ,hardfacing on all teeth faces and gage.Inserton TH217 heel row and gage for gage protection. | 0.351.20 | 10050 |
TH217 | 217 | ||||
TH316 | 316 | Hard with high compressive strength and abrasiveness(hard shale,hard sandstone,hard limestone and dolomite,etc.) | Short teeth with less teeth space,heel row densified with"T"shaped teeth,and hardfacing on aall teeth faces and gage.For TH317,carbide inserts are used on gage for improved protection. | 0.701.40 | 8045 |
TH317 | 317 | ||||
TH346 | 346 | Very hard with high compressive strength and abrasiveness,such as quartzite,sandy quartzite,chert, pyrite and granite,etc. | Short & thick teeth with special ring type crest are utilized,with" "shaped teeth in heel row and hardfacing on all teeth faces and gage.For TH347,carbide inserts are used on gage for improved protection. | 1.101.40 | 7050 |
TH347 | 347 | ||||
