Size:20mm*20mm to 600mm*600mm WT:0.8mm-20mm Length:3m,5.8m,6m or as to your request Usage:Greenhouse,post,structual steel PRE-GALVANIZED SQUARE STEEL PIPESIZESIZE toleranceW.TThickness Tolerance20MM*20MM-600*600MM±0.030.8--20MM±0.02Length 2--12M , according to customers' requirementsSurface treatmentoiled,painting color,hot dipped galvanized,pre-galvanized International Standard ISO 9001;2000, ...