| Grade:STM-R690 STM-R780Specification(mm):36-89*4-10Standard:YB235 Q/BQB230Application:For geologic drillingChangzhou yuanyang steel tube Co.,Ltd is the professional manufacturer and supplier of structural seamless steel tube.We serve our customers with the best quality products and fastest delivery and take the "Customers First and best service" as principle, the whole staff of our company has united as one to develop with creation and innovation. | 
