● the base material of galvanized steel profiles shall be continuous hot-dip galvanized steel sheets produced by Angang, Shougang, Baosteel, WISCO and Longgang. The hot-dip galvanized steel sheets shall meet the product requirements of dc51d+z-40/40 in Baosteel enterprise standard q/bqb 420-2009 continuous hot-dip galvanized + zinc iron alloy coated steel sheets and strips and dx51d+z-80 in Angang enterprise standard q/ asb385-2009 stamping and structural continuous hot-dip galvanized steel sheets and strips. The surface shall be subject to chromium free passivation, The sum of double-sided galvanized layer thickness shall not be less than 80g, and the minimum local thickness of polyester powder spraying thickness shall be ≥ 60 μ m。

● p66 wear-resistant nylon is used for the decorative cover at the bottom of the column, the decorative cover at the end of the handrail, and the connecting sleeve of the vertical rod. The decorative cover adopts the male and female plug-in and rear installation method.

● the surfaces of all railing shutter components, including galvanized steel profiles, decorative parts and decorative flowers, shall be sprayed with AkzoNobel or DuPont polyester powder. The minimum thickness of local coating on the surface of galvanized steel profiles shall not be less than 60 μ m. The minimum local thickness of aluminum profile and die cast aluminum surface coating shall not be less than 40 μ m。