Design Nomenclature / Physical Model Making
Sheet metal
Also called sheet, sheet goods, sheetmetal, fabrication
Metal supplied as flat stock and worked cold — cut, bent, punched, rolled. Because the material will not stretch far, the achievable form is bound to what unrolls flat: bends about straight lines, cylinders and cones. Anything with double curvature needs a dart, a stretch-form, or a weld.
In practice
Thickness is quoted in gauge in most shops, and the gauge number runs backwards and differs between steel and aluminium. Ask for a dimension. Every bend then carries a minimum inside radius and a bend allowance, and the flat pattern is not the sum of the outside faces.