... 15-600*600mm. 5.Surface:Black painting or oiled steel square tube/pipe 1)Thickness:0.5-30mm2)Size(dia.): ... a large company specializing in the production and selling of square, round, rectangular pipe surfaced with galvanized coating, polish, black ... establishment, we have always adhered to the business policy as "Quality for Survival, Product for Development, Credibility for Cooperation and Service ...