Integral heavy weight drill pipes are manufactured from AISI 4142H-4145H modified drill collar material , thick-walled pipe called integral heavy weight drill pipe was developed to provid a gradual transition from the heavy weight drill collars to the relatively light weight drill pipe. This intermediate weight pipe has a wall thickness of approximately, and it helps prevent stress concentration at the� top of the drill collars. It also allows you to drill at higher pms, reducing torque and differential pressure sticking. It is intended primarily for directional drilling. Because it bends easily, it simplifies directional control and�  minimizes connection fatigue problems common to high angle or horizontal drilling. The reduced number of pipe failures and increased drill stem service also make it appropriate for some straight hole applications. Specification OD ID connection Body Weight mm in mm in Style OD Inner and outer thread Upset mm in Mmd center area Mm � End area Type I�  (Length is 9300mm for one piece) ZH-J66-6 5/8FH-I 168.3 6 5/8 114.3 4 1/2 6 5/8FH 209.6 8 1/4 195.70 184.2 176.21 965KG ZH-J55-5 1/2FH-I 139.7 5 1/2 92.1 3 5/8 5 1/2FH 177.8 7 170.7 152.4 144.5 730KG ZH-J50-NC50-I 127.0 5 76.2 3 NC50 168.3 6 5/8 154.0 139.7 130.2 700KG ZH-J45-NC46-I 114.3 4 1/2 71.4 2 13/16 NC46 158.8 6 1/4 145.3 127.0 117.5 585KG ZH-J35-NC38-I 88.9 3 1/2 52.39 2 1/16 NC38 120.7 4 3/4 116.3 101.6 92.1 370KG ZH-J29-NC31-I 73.03 2 7/8 50.8 2 NC31 104.8 4 1/8 100.4 84.1 81.0 220KG Type II�  (Length is 13500mm for one piece) ZH-J50-NC50-II 127.0 5 76.2 3 NC50 168.3 6 5/8 154.0 139.7 130.2 945 ZH-J45-NC46-II 114.3 4 1/2 71.4 2 13/16 NC46 158.8 6 1/4 145.3 127.0 117.5 790