Steel chair frame (zinc plated) 1.The lowest price in ALIBABA 2.ISO9001-2000 3.3.OEM available Steel chair frame (zinc plated) 1 tube :iron carbon steel,stainless steel ,aluminum 2 tube thickness:1-1.8mm 3 tube diameter:19-30mm 4 Surfacetreatment:powder coated, plating ,polishing,chrome plated