Thin aluminum sheet refers to aluminium sheets with thick between 0.2mm ~ 2mm ( 14 ga – 30 ga ). For example, the commonly used aluminum sheet thicknesses are 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm ( 20 ga ), 0.9mm, 1mm ( 18 ga = 1.0mm ), 1.1mm, 1.2mm, 1.3mm (16 ga), 1.4mm, 1.5mm, 1.6mm ( 14 ga ) etc