See all Blog Posts Sheet Metal Gauge Chart Category: Metal Man Knows Posted: February 1, 2018 When working with sheet metal, it is common for the term “gauge” to be used. Someone unfamiliar with the gauge system may not understand what is meant by 18 gauge steel, for example. To help, this blog will explain the gauge system and features a sheet metal gauge chart. How are sheet metal gauges used? Gauges are used to specify the thickness of a sheet metal. Gauges are neither standard nor metric and the values are independent of those measurement systems. A gauge conversion chart can be used to determine the actual thickness of sheet metal in inches or millimeters. For example, 18 gauge steel, according to a gauge conversion chart, is 0.0478 inch or 1.214 millimeter. The gauge number “18” holds no relevance to the actual measurements. There are several different gauge systems used today, with specific gauge designations used for specific metal types. For example, in one gauge system, 18 gauge steel measures 0.0478 inches thick, but 18 gauge aluminium is 0.0403 inches thick. Because of the varying thicknesses, a gauge chart should be used to ensure the metal meets the required dimensions. History of the gauge system The gauge system has long history in metal fabrication. It most likely originated from the British wire industry before the standard and metric measurement systems were widely adopted. At that time, gauges were used to describe the diameter of the metal wire being drawn. Since then, it has remained a prevalent method of designating the thickness of both wire and sheet metal. Sheet Metal Gauge Chart Gauge Chart GaugeNumber ImperialEquivalent in MM 10 3.25 12 2.64 14 2.03 16 1.63 18 1.22 20 0.91 22 0.71 24 0.56 26 0.46 Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminium, tool steel, engineering steel, brass, bronze and copper. We carry a wide range of shapes including: bars, tubes, sheets and plates. We can cut metal to your exact specifications. Visit one of our 7 locations in the United Kingdom today. Share: Facebook Twitter LinkedIn E-Mail Tags: gauge, sheet Related blog articles What is Cast Iron? The Difference Between Cold Drawn and Extruded Metals What is Dexion?