... 7-610 mm 4.Place of origin:China 5.Certificate:API.ISO9001:2000.BV structure seamless pipeHebei shengtian (group) ... ASTM A53 , ASTM A179, ASTM A210 ,ANSI B36.10, GB 5310,10# 20#, 45#,GB 3087, GB/T 8162 ,GB/ ... ,Q345B,16Mn, 10# 20#,45# S235JR, S355JR;ASTMA252 Gr.2,Gr.3; ST37,ST42,ST52;Gr.B,X42,X46,X52,X56,X60,X65 ... , Italy, France, England, the Netherlands,Belgium, etc13.CertificatesAPI 5L; ISO9001:2000