The Sheet Metal Gage helps you to accurately determine the thickness of uncoated sheet metal, plate iron and steel. The Gage measures U.S. Standard sheet metal sizes from 0 to 36. This heavy duty gage is made from hardened and tempered steel, and is stamped with sheet metal sizes on the front and their decimal equivalents on the back. U.S. Standard Sheet Metal Gage with range from 0 to 36. Works with uncoated sheet metal, plate iron and steel. Heavy gage hardened and tempered steel with a satin finish. Gage sizes are stamped on front; decimal equivalents are stamped on back. 3-1/4 in. diameter; 3/32 in. thick.