... 1-standards:ASTM,GB,DIN,JIS.etc 2-material:carbon steel, alloy steel et ASTM 20# seamless steel pipe ... SpecificationsChina StandardSteel GradeStandardseamless steel tubesand pipesfor structural purposeGB/T8162-199910, 20, 35, 45, 40Mn2, 45Mn2, 27SiMn, 20Cr, 40Cr, 20CrMo ... 2-1997 ASTM A161-94Seamless steel tubesfor petroleum crackingGB9948-8610, 20, 12CrMo, 15CrMo, 1Cr2Mo, 1Cr5Mo, JIS G3441-1988 ...