Coating mass
Zinc coating is specified as total coating mass on both sides, in g/m². Designations such as Z120, Z180 and Z275 are common in procurement; a higher number is a heavier coating and a longer corrosion life in the same environment. Always state the coating mass — "GP sheet" alone does not define it.
Other parameters
- Base-metal grade (general / forming / structural designation)
- Spangle: regular, minimised or zero spangle
- Surface treatment: passivated (chromated / chrome-free) or unpassivated, oiled or dry
- Skin-passed finish (GPSP) where a smoother surface is needed for painting or visible panels
- Thickness, width and length / coil dimensions