Aluminum and aluminum alloy is a high electrical and thermal conductivity of the metal material in its natural state vulnerable to surface passivation, surface oxidation A1203,3H20 in wet acidic conditions, hydrated alumina itself more stable, so aluminum and aluminum alloys window and door profiles made of a high-performance anti-corrosion material. Aluminum doors and windows and therefore preservation site is mainly in hardware, hardware galvanic corrosion is not only in itself, but also by the impact of aluminum electrode. Under certain conditions, the corrosion will be uninterrupted. Therefore, aluminum doors and windows with hardware in the design process to take into account material, surface protection particularity.

PVC profile is a non-metallic material of high insulation, no electrode corrosion phenomena on metal parts, steel doors preservative mainly in hardware, as long as the hardware components of each selection properly, then better surface protection process, you can achieve durable purpose.