What Is AZ150?
AZ150 is a coating weight: 150 g/m² of aluminum-zinc alloy on steel sheet, counted across both faces, per ASTM A792. The letters name the alloy, the number sets how much of it there is — and coating weight is what long corrosion warranties are written against.
The short definition
AZ150 is a coating weight designation. The letters say what the coating is — AZ for aluminum-zinc — and the number says how much of it there is: 150 grams per square metre, counting both sides of the sheet. The standard behind it is ASTM A792, the specification for aluminum-zinc alloy-coated steel sheet.
It is a quantity, not a quality grade. AZ50 and AZ55 exist for interior and light-duty work; AZ150 sits at the heavier end of what is commonly rolled for exterior building products.
How to read the code
Because the number is a total across both faces, a thicker sheet does not automatically carry more coating, and comparing an AZ number to a Z number is not apples to apples: aluminum-zinc buys more corrosion resistance per gram than zinc alone.
Why the number matters
Coating weight is the reservoir. Corrosion consumes coating over time; the more of it there is, the longer the steel underneath stays protected. That is the whole reason exterior products specify a coating weight at all rather than just naming the alloy.
It is also the number that makes long warranties possible. A warranty against perforation is a claim about how long the coating will hold, so it has to be written against a specified weight — not against "galvanized" as a category.
Where ecFence lands
ecFence panels are AZ150 aluminum-zinc coated, with an epoxy primer and an SMP topcoat over the coating on both faces. The panel system carries a 25-year warranty.
When you are comparing quotes, ask for the coating code in writing. "Galvanized steel" tells you almost nothing; "AZ150 per ASTM A792" tells you exactly what you are buying.