The first and most important rule of reading and understanding a steel gauge chart is using the right one. Meaning coated steel gauges like galvanized are vastly different from uncoated steel like hot rolled and cold rolled gauges.
Standard gauge numbers and sizes were developed based on the weight of the sheet for a given material and coating. The equivalent thicknesses differ for each gauge number. You must use the specific gauge chart for each material to learn the right thickness.
So, in this case, you’ll need the Cold Rolled Gauge Chart.
Now that you have the right chart, it’s time to understand how it’s measured. Gauges are different from other measurement units such as inches or centimeters. That’s due to there being no universal thickness measurement for metal during the 19th century.
The British iron wire industry adopted metal gauges over other traditional units like inches as the primary unit of measurement, and thus it’s become the standard for the steel industry, being used across sheet metals.
When looking at a gauge chart, the key to understanding it, including our cold rolled chart, is to look at the number. Gauges range from 3-31, each has a specific thickness assigned to it for the material based upon its weight.
The general rule across all gauge charts is the larger the number, the thinner the steel. The inverse is also true, as the gauge number gets lower, the thicker the steel gets. But, those numbers do not give you specific dimensional values. Follow the chart for the exact numbers you need.
If you’re looking for an even simpler solution to understanding the correct gauge, weight, width, and measurement conversions of any steel product, use our steel calculator Unravel.
Whether calculating gauges for cold rolled, hot rolled, and coated materials, looking for sheet metal or coil measurements, or just looking for unit conversion to inches and pounds, Unravel does the work for you.