The one-piece drill collar pipe is made of AISI 4145H alloy steel, meets API specifications and SY/T5146 standard. The material is forged and formed as a single unit on a precision forging machine and heat treated in a well furnace for heat treatment, and the wear resistant tapes are spray-applied to the joints at both ends and a thickened area in the middle. This allows the spraying of 100XT and 300XT wear-resistant materials authorized by ANKE in the USA. The thread can be cold-rolled, copper-plated or phosphated, and double-arm threads and other special threads can be processed according to specifications.
Type I
Type II
Mechanical properties
| Yield point Rp0.2 | Tensile strength Rm Mpa Rm Mpa | Elongation Factor A％ | Brinell Hardness HB | Charpy's percussion work Akv Gab |
| ≥758 | ≥964 | ≥13 | 285-341 | ≥54 |
Dimensional Tolerance
| Outer Diameter | Bore | Length | Outer diameter of the connection with internal and external threads | Size of the thickened part | |
| D | B | ||||
| ±0.8 | ±1.60 | ±150 | ±0.8 | ±0.75% D ±0.75% D | ±0.80 |
Dimensions of one-piece drill collars
| Specification | Outer Diameter | Bore | Compound | Pipe Body | Вес Weight | ||||||||||||||
| mm | in | mm | in | Type | Outer Diameter | Chamfer arm of internal and external threads | Size of the thickened part | kg medical history | |||||||||||
| mm | in | Middle part | The end | ||||||||||||||||
| Type I (length of one pipe 9300 mm) | |||||||||||||||||||
| ZH-JZ66 65/8-1 | 168.3 | 6 5/8 | 114.3 | 4 1/2 | 6 5/8FH/2 | 209.6 | 8 1/4 | 195.70 | 184.2 | 176.21 | 965 | ||||||||
| ZH-JZ55 51/2FH-I | 139.7 | 5 1/2 | 92.1 | 3 5/8 | 5 1/2FH | 177.8 | 7 | 170.7 | 152.4 | 144.5 | 730 | ||||||||
| ZH-JZ50 NC50-I | 127.0 | 5 | 76.2 | 3 | NC50 | 168.3 | 6 5/8 | 154.0 | 139.7 | 130.2 | 700 | ||||||||
| ZH-JZ45 NC45-I | 114.3 | 4 1/2 | 71.4 | 2 13/16 | NC46 | 158.8 | 6 1/4 | 145.3 | 127.0 | 117.5 | 585 | ||||||||
| ZH-JZ35 NC38-I | 88.9 | 3 1/2 | 52.39 | 2 1/16 | NC38 | 120.7 | 4 3/4 | 116.3 | 101.6 | 92.1 | 370 | ||||||||
| ZH-J29-NC31-I | 73.03 | 2 7/8 | 50.8 | 2 | NC31 | 104.8 | 4 1/8 | 100.4 | 84.1 | 81.0 | 220 | ||||||||
| Type II (length of one pipe 13500 mm) | |||||||||||||||||||
| ZH-JZ50-NC50-H | 127.0 | 5 | 76.2 | 3 | NC50 | 168.3 | 6 5/8 | 154.0 | 139.7 | 130,2 | 945 | ||||||||
| ZH-JZ45-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 | ||||||||
