1. dia 28mm lean pipe for display rack system 2.pipe outer dia 28mm 3.applied to assemble diy pipe rack, handcart Details of lean pipe: Material:Extruded plastics (Outside ) + Galvanized Steel tube (Middle) + Antirust Coat (Interior)Technics:Cold RolledDegree of hardness:90External diameter:27.5mm- 28.0mmInternal diameter:19.5mm-24mmThickness of steel tube wall:0.8mm ,1.0mm,1.2 mm,1.5mm, 2. ...