Modern innovation has taken steel to a whole new level. With a coating of Aluminium-Zinc over the ordinary steel, this technology provides for longer service life and extends the durability of modern coated steel. Aluminum Zinc coating is done by continuously hot dipping steel in a formulation of Aluminium (55%), Zinc (43.5%) and Silicon (1.5%). This coating was developed by the Bethlehem International Engineering Company (BIEC Inc.) in the USA, now a fully owned subsidiary of BlueScope Steel, Australia. All legitimate producers are registered with the license authority BIEC.
The patented coating protects the steel in two ways; the aluminium component of the coating provides a tough physical barrier between the extreme atmospheric conditions and the inner core of steel. Furthermore, the zinc in the coating provides sacrificial protection and also protects the steel at the cut edges. Conventional galvanized coatings consist primarily of zinc and its atmospheric corrosion‐resistant protective life is directly proportional to the original coating thickness. In the case of the AZ coating, there is an additional aluminium barrier coating, as well as a zinc‐rich component that effectively provides sacrificial protection against corrosion at cut edges and where there is other mechanical damage (deep coating surface scratches due to handling damage etc.)