... window hollow section size: 28*28, 38*38 thickness: 0.8-1.2mm material: q195-q235 finishi: black annealed Steel window hollow sectionsize ... 304 High pressure steel prof...tolernace: normal standard toleranceShape: round,square,rectangularsurface: pickled, acid, polished, black,ectcertificate: ISO, BV, ... JIS, T14975, etc.4.Out Diameter: 6-830 mm5.Wall Thickness:0.5-40 mm6.Length:SPECIFIC OR AT RANDOM ...