4 x 10 x 24 gauge
4 x 10 x 26 gauge
Hot-dip galvanizing is the process of coating steel with a thin zinc layer by passing the steel through a molten bath of zinc. Having a temperature of around 460C. Zinc "rusts" to form zinc oxide, a fairly strong material that stops further rusting, protecting the steel below from the elements.
Galvanized steel is widely used in applications where rust resistance is needed, and can be identified by the crystalization patterning on the surface (often called a "spangle").