... Quick Details Standard: BS, JIS, GB, DIN, ASTM, APIStandard: BS 1387, BS 1139, BS 6363, ... according to requirement.Black square tube with A53 material 1,mild steel 2,10-15days ... ISO.BV.QC certificate Black square tube with A53 materialDimensions:15*15mm -200*200mmThickness:0.6mm- ... St33, St37-2, SS330, SS400, ASTM A 106B, ASTM A53, X42Quality:Manufactured to meet ISO9001, ASTM, API, SAE, DIN, BS, ...