G90 galvanized steel sheet is a coating thickness designation specified under ASTM A653 galvanizing specification. It indicates a zinc coating of 0.90 ounces per square foot (oz/ft2).
G90 galvanized steel coils are cold-rolled steel sheets hot-dipped in zinc coating for increased durability. Specifically, these galvanized steel coils should have a triple-spot test (TST) average minimum zinc coating weight of 0.90 ounces per square foot on both sides or a minimum of 0.32 ounces per square foot on each side.
Meanwhile, if it’s under a single-spot test (SST), the steel must have an average minimum coating weight of 0.80 ounces per square foot on both sides.
The standard rule for protective coating is that the heavier the coating, the higher its durability. Hence, G90 galvanized steel coil has the most extended service life compared to other coating designations, G60, G40, and G30. Products under the G90 specification are primarily used in high moisture environments because they have higher resistance to corrosive environments.
