Sheet Metal Gauge Chart

Gauges are used to specify the thickness of a sheet metal. They’re neither standard nor metric, so their values are independent of those measurement systems. Below you can use a gauge conversion chart to figure out the thickness of your sheet metal you’ll need. According to a gauge conversion chart, 18 gauge steel is 0.0478 inches or 1.214 millimeters thick. It doesn’t matter how big the gauge number is.

The gauge indicates the standard thickness of the sheet metal for a specific material. As the gauge number increases, the material thickness decreases. When it comes to metal fabrication, metal thickness based on gauge is an important element. This Gauge Chart is vital when it comes to choosing the correct metal thickness and components for your project. The table below is an easy to understand resource that allows you to determine gauge by metal thickness in both inches and millimeters, for standard steel, stainless steel, galvanized steel, aluminum, copper, and brass.

There are several different gauge systems used today, with specific gauge designations for specific metal types. For example in one gauge system 18 gauge aluminum is 0.0403 inches thick, but 18 gauge steel measures 0.0478 inches thick. Because of the varying thicknesses, its a smart idea to get used to useing a gauge chart to check the dimensions. Feel free to download our version below and to keep with you on your computer or phone.

Sheet metal thickness gauges for steel are based on a weight of 41.82 pounds per square foot per inch of thickness. This is known as the Manufacturers’ Standard Gage for Sheet Steel. For other materials, such as copper, aluminum, or brass, the thicknesses will vary, hence a key to determine the correct gauge below!

Not sure the metal gauge required for your project? This Gauge Chart should help you determine which gauge corresponds to each thickness for each type of metal.

Gauge Chart




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