Metal Thickness Confusion

Metal Thickness

For the most part, Metal Plate, and Sheet is measure with Fractional or Metric Decimal Dimensions.

The Larger the Decimal number, the thicker the metal is that it represents.

That’s easy! But woops! Somebody, sometime ago came up with the guage system for measuring the thickness of metals.

This system of measuring the thickness of metals is the opposite of normal dimensional measuring of the thickness. This systems numbering system goes up in value as the actual thickness gets smaller, or thinner. 18 ga. is thinner than 10 ga.

What’s up with that?

Take a spin around the internet on that question, and it’s soon apparent that it’s even more confusing the more you look into it.

One suggestion is that it has something to do with the Weight of a Cube Ft. of a given material. That may be true, but it’s a mathematic mess to figure it out.

One other suggestion is that it has something to do with the diameter of Wire, and how many times it needs to be drawn thru dies (Squeezed, that is) to get it to the size that it is. Ie. 16ga. = 16x thru the drawing dies to get it to be .0598″ thick. Since that process was derived from the 1800s, this just is not the case any longer.

One place even suggested that the Guage # was based on the amount the material weighs as a round bar, or wire diameter in feet. That is if the material is 16 ft. long, and weighs 1 lb. that is 16ga. material. If the material is 10 ft. long, and weighs 1 lb. then it is 10ga. material. That’s Milarky.

Since Warehouses, and Mills still list Sheet Metal Materials in Guage numbers, and still sell it that way, the best way to figure out how thick the material you are refering to is to look it up in a chart.

Check out the handy chart provided below.

SHEET METAL GUAGES