Thickness conversion charts exist for steel beams, wooden boards, coatings of paint, sheets of metal and a large number of other building materials and objects. As thickness is generally measured in standardized units of length such as meters or feet, thickness conversion charts can be easily generated for many materials.
MESteel.com contains a steel wire thickness conversion chart that matches gauge number, which measures the thickness of a wire, to the measurements in inches and millimeters specified by the U.S. Standard Gauge and Birmingham Wire Gauge systems. Frii.com offers a millimeter to inch conversion table for the various gauges of sheet metal thickness. Thickness conversion charts are also commonly used when determining coating thickness; an example coating thickness conversion chart is available on BryCoat.com