steel tubing material :Q195 wall thickness :0.3-2.0mm shape : rectangular length : 3-12m we are a manufacturer for ... steel tubing SHAPErectangular SIZES8*16mm,8*18mm,9*19mm,10*20mm,10*22mm,11*21.5mm,11.6*17.8mm,12*14mm,12*34mm12*48mm ... *30mm,15*35mm,15*88mm,16*26mm,.17.5*15.5mm,18*35mm,19*38mm20*35mm,20*30mm,20*40mm, 22 ...