What Is Sheet Metal Gauge? Metal Gauge Chart For Steel, Stainless, Aluminum, Brass, And More:

If you’re an engineer, you opine that having a sheet metal gauge chart is invaluable. It saves time and effort because you don’t have to flip through a handbook or search the internet to determine metal thickness for CNC machining. 

We’ve organized all of the gauge information into one manageable guide that’s easy to navigate and search through. Even better, we have included the sheet metal gauge chart for all commonly used metals, including brass, copper, stainless steel, aluminum, sheet steel, and galvanized steel. Read on.

What is Sheet Metal Gauge? – Metal Gauge Thickness

Sheet metal is measured by its thickness or gauge. The lower the gauge, the thicker it is (except for Zinc). Conversely, larger gauges are thinner than smaller ones of the same type of metal. Sheet metal’s thickness is defined in thousands of inches (or mils) for each respective scrap yard.

The most common sheet metal gauges (also known as gage) range from 30 to 14, and they are measured either in thousandths of an inch (12 GA), or millimeters (12 mm).

However, measuring sheet metal gauges by the thousandth of an inch (or mil) is more common among American scrap yards. There are gauge numbers like 000000 and 0 for aluminum and stainless steel. A metal thickness of 000000 gauge is larger than 0 gauge.

The largest gauge, in this case, is 0000000, which is equivalent to 0.5 inches. The smallest gauge is 0 and equals 0.1875 inches.

How Does Sheet Metal Gauge Work?

A gauge chart is simplified to make it easier for you to understand. It only consists of the sheet metal gauge numbers and their respective thicknesses in inches or millimeters.

This makes it simple to select the ideal material for the CNC machining process. It reduces the error margin for gauging sheet metal of the same make.

How to Use Metal Gauge Chart?

It’s simple. Just find the type of metal you want on our metal gauge chart and look at its equivalency between gauges and thickness/millimeters to get its thickness. For example, if you are searching for the metal steel sheet gauge, look at the steel row on the chart.

However, you should note that sheet metal gauges are not standard or metric. All the figures/numbers provided are independent of measurement systems and do not mean real measured values.

Additionally, the sheet metal gauge chart has been organized into groups that correspond to the respective type of material. That way, it is easier to look for a specific metal material instead of looking through it haphazardly to find what you need.

You should note that the same gauge number may present different thicknesses for different materials. For example, 37 gauge of aluminum equals 0.0045 inches thickness while 37 gauge of stainless steel equals 0.0066 inches thickness. As such, you should only check the thickness against the specific metal you need to use.

Different Gauge Size Standards for Sheet Metal

There is no single metal gauge standard that applies to all metals. The thickness of a metal is determined by its respective weight.

Manufacturers adopt different standards for their products, and sheet metal gauges go by various nomenclatures such as MSG, G, SWG (Standard Wire Geometry), AWG (American Wire Gauge), and Mils.

The Manufacturers Standard Gauge (MSG) provides the gauge/thickness for stainless steel, standard steel, and galvanized steel. On the other hand, the American Wire Gage (also known as the Brown and Sharpe Gage) is used to measure the thickness of non-ferrous metals, including brass and aluminum.

In the UK, the most popular metal thickness standard is the Birmingham Gauge (BG). However, it is not widely used. It is mostly used with metals in tubing and strip.

Finally, there exists a standard gauge specially designed for Zinc. In this case, the sheet metal gauge number is equivalent to the weight of Zinc in pounds. As such, the higher the gauge number, the thicker the sheet.

Related article: Plastic Gauge Thickness Chart 

Sheet Metal Gauge Chart for Different Materials

This section offers a sheet metal gauge chart that lists different sheet metals and their respective thicknesses measured in inches or millimeters. It shows you the equivalent number of sheet gauges for your reference. It is a useful tool when you want to convert the gauge to inches or millimeters.

Each type of metal has its chart. We have included charts for galvanized steel, sheet steel, copper, aluminum, stainless steel, and brass. The most commonly applied gauge is that of steel.