Gauge thickness and material weights · Lesson 2 of 4

Gauge thickness and material weights: materials, standards and design constraints

The three steel gauge tables side by side, why the galvanized table is heavier, how aluminum, copper and zinc are sized, which standards sit behind the numbers, and the AFS limits that depend on thickness.

You will be able to: Read thickness and weight for galvanized and stainless steel, aluminum, copper and zinc from the right table or unit, and state which AFS limits depend on thickness.

11 min · 12 slides · 8 questions

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Slide 1 of 12

Steel: three tables side by side

Steel has three common tables for the same gauge numbers: the 1893 U.S. Standard, a sheet-steel table and the galvanized table.

At 16 gauge the galvanized table gives 0.0635 in.

At 16 gauge the U.S. Standard table gives 0.0625 in.

At 16 gauge the sheet-steel table gives 0.0598 in.

Notice that the galvanized table is thickest at every gauge and the sheet-steel column is thinnest. Sources: 15 U.S.C. 206 (U.S. Standard); the AFS register, checked against Steel Market Update (galvanized); Continental Steel & Tube chart (sheet steel).

Sources

AFS material register (alloys, thicknesses, weights and expansion coefficients) - Architectural Flashing Supply
15 U.S.C. 206 - Standard gauge for sheet and plate iron and steel (U.S. Code, 2009 edition; Act of March 3, 1893, 27 Stat. 746) - U.S. Government Publishing Office (govinfo)
Gauge and Weight Chart (sheet steel, galvanized steel, stainless steel, aluminum columns) - Continental Steel & Tube Co. (metals distributor)

Glossary

U.S. Standard Gauge: The 1893 gauge for sheet and plate iron and steel, written into federal law as 15 U.S.C. 206. It lists a weight for each gauge number, and AFS's register uses it for stainless steel.
Manufacturers' Standard Gauge: The name often given to the uncoated sheet-steel gauge table, in which 24 gauge is 0.0239 in and 1.000 lb per square foot.
Galvanized sheet gauge: The gauge table for zinc-coated steel. It is a weight gauge for the finished sheet, and in 1931 each gauge weighed 2.5 oz per square foot more than the same U.S. Standard gauge.
Density: Weight per unit of volume, such as 0.2833 lb per cubic inch for steel. Multiplying density by thickness and 144 gives weight per square foot.
Weight per square foot: The weight of a piece of sheet 12 in by 12 in, in lb per square foot. For copper it is the ounce rating divided by 16.