2.Formation or layer :soft ,medium soft ,hard, medium hard, very hard formation
3.Bearing sealed: metal sealed (HJ), rubber sealed(HA), not sealed(W)
4.Material: alloy steel, tungsten carbide insert
5.Certification: API & ISO9001
6.Size:3 7/8 ,5 1/2, 6 1/2,7 7/8,8 1/2,8 3/4,10 5/8,12 1/4,13 3/4, 17 1/2,22, 24,26
7.Application:Petroleum & gas ,water well ,mining and tectonic industries ,oil field, construction, geothermal, 8.directional boring, and underground foundation work
9.Delivery terms:By sea or by air
10.Payment terms:T/T
11.IADC Code:417 427 437 517 527 537 617 627 637 737 837 832 415 425 435 445 525 625 635 416 427