Welded Steel Tubes 1.Standard:ASTM,ANSI,API,GB,DIN,JIS,EN 2. ... 3.Thickness:0.35mm-2.5mm 4.Material:Q195,Q235 welded Steel Tubes1) Available shapes: round, square, rectangular, bread shaped 2 ... , GB and SY/TWe can produce precision and high-frequency welded steel tubes and pipes with all possible dimensions and shapes available.