... ,APISPEC5L,API5CT,ASTMA53/A106,JIS,BS1387,etc.3.Steel Grade: Q235B,Q345B,API5L Grade B,X42~X80,16Mn,20#ST37~ST52 ... end caps, varnish or as per customers' requirementsProduct namewelded steel pipe/tubeOut diameter20-219mmWall Thickness0.9-12mmStandardGB/T3091-2001Quality gradeFirst gradeTolerence ... black paintingAll the production process are made under the ISO9000. API5L Pipeline/ERW Steel Pipe/