... certificate Quick Details Standard: BS, JIS, GB, DIN, ASTM, APIStandard: BS 1387, BS 1139, BS 6363, ... Black square tube with A53 material 1,mild steel 2,10-15days delivery time 3,15- ... , St37-2, SS330, SS400, ASTM A 106B, ASTM A53, X42Quality:Manufactured to meet ISO9001, ASTM, API, SAE, DIN, BS, ... size we can provide for you. Square steel tube (mm )Rectangular steel tube (mm)ODWTODWTODWTODWT15*150.6--1. ...