Drill pipe is an important component which connects rig and broach, and is used for transmitting the power to break the rock under the well and transporting the flushing medium.
OD：Φ33mm~Φ127mm；WT: 5.0mm~10.0mm；Length: 6.0m~12.0m
The main materials or grades
ZT380、ZT 490、ZT 520、ZT 540、ZT 590、ZT 640、ZT 740Executive standard
GB/T 9808-2008《Seamless steel pipe for drilling》
JIS G 3465-2006《Seamless steel pipe for drilling》
GB/T 16950-2014《Geological core drilling tool》
抗拉强度Tensile strength Rm/MPa
Notes：a Yield strength of Grade ZT520 is measured by Rp0.5.
bTensile specimens of Grade ZT520 adopt S4, S5 or S6 according to GB/T228 standard.
OD tolerance：-0.5%D~+1.0%D，WT tolerance：-10%S~+12.5%S，Straightness≤1.0~1.3mm/m。
Geological drill pipe, is mainly used for transmitting power and transporting drilling mud which need to have good mechanical properties. It can be applied to the environment with high temperature and corrosive medium（such as H2S,CO2,etc）.