The aluminum – Zinc alloy for 55% Al-Zn alloy – coated steel coils consists of 55% aluminum, 43.4% zinc and 1.6% silicon, solidified at 600 degree Celsius high temperature. The whole structure is quaternary Al-Fe-Si-Zn compound, which becomes a protection layer on the steel sheet to prevent penetration of corrosive factors effectively . All painted steel panels shall receive average regular polyester coating mass in triple-spot test AZM120-AZM 150.Panel material shall confirm to yield strength of 50 ksi (345 N/mm2) or 80 ksi (550 Mpa).Many colors are available to match the environment and attach value to appearance. Superior resistance against environment : Heat resistance, corrosion resistance, weather proof, etc. Formability, impact resistance, and acid/alkali resistance are the major reasons for the popularity of pre-pointed 55% Al-Zn alloy-coated and galvanized steel sheets. The pre-treatment section prevent the surface of the steel sheet providing the surface with enhanced paint adhesion characteristics. The painted surface’s resistance to damage from bending, impact and corrosion is also improving.