Drill String Cross-over Sub uses AISI4145H chromium-molybdenum steel, execute API specification.We can produce the same-dia type, reducers type and L-type three types, the screw can be cold thread rolling, copper or phosphate treatment.
40 Cr hot rolled round bars and forged round bars are the steel of the standard of GB/T 3077-1999 in China, any need in 40Cr hot rolled round bars and forged round bars ,please contact us!
Although GB/T700 Q235A is china standard, GB/T700 Q235A I beam /angle/ channel steel is one kind of popular steel in the world. KUNFENG export although GB/T700 Q235A is china standard for many years. We didn’t received one time bad value of GB/T700 Q235A