Many different types of metal can be made into sheet metal, including aluminum, brass, copper, steel, titanium, tin and stainless steel. Sheet metal is available in a variety of different metal types and thicknesses. Choosing the right sheet metal gauge and thickness is essential to any metal fabrication project.
Similar to wire, sheet metal thickness is measured in gauges: the higher the number, the thinner the sheet metal. A gauge is a traditional, non-linear measurement. The most commonly used sheet metal sizes range from 30 gauge (thinner) to 7 gauge (thicker).
A sheet metal gauge tool is used to measure metal thickness, and show both the gauge number as well as the thickness of the metal in thousandths of an inch. Different gauge thickness applies to different metals. Since ferrous and non-ferrous metals of the same gauge have different thicknesses, different metal gauge tools are used to measure ferrous and non-ferrous metals.
For example, a sheet of galvanized steel with a gauge thickness of 10 is 0.1382 inch, whereas 10-gauge standard steel measures 0.1345 inch and stainless steel measures 0.0120 inch. Galvanized steel sheet metal measuring 30 gauges equals 0.0157 inch, but the same gauge standard steel sheet metal measures 0.0120 inch and 30-gauge stainless steel measures 0.0125 inch. It should be noted that aluminum is usually classified by inches rather than gauge, as there is no official gauge standard for aluminum. The difference in thickness for each gauge size is based on the weight of the sheet for each different type of metal. This handy sheet metal thickness chart shows gauge size by inches and metal type.