The General Tool Sheet Metal Thickness Gauge 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. Take a look at this video to see how it is used. https://www.penntoolco.com/general-sheet-metal-thickness-gauge-21/ #blacksmith #cncowners #craftsman #customengraving #engraving #fabrication #fabricator #fabshop #handstamping #homemachineshop