tata pipes 1.Grade: 20#,45#,16Mn, 27SiMn,25Mn 2.Standard: API, GB 3.Diameter:50-300mm 4.Thickness:2-50mm tata pipesProduct varietyProcessing modeDiameterLengthLinearityPrecisionRoughness of inner holeCold drawn50-300less than13.5M 0.3-1.0H8-H100.8-1.6Honing50-300less than 13.5M1000H8-H90.4-0.8Cutting Rolling50-300less than7.5MH80.4 Size toleranceInner diameter warp of wall thicknessH8H9H1050-80+0 ...