Livingston Jewelers

Introduction to metal gauges

Sheet metal gauge is a measure of thickness where larger numbers = thinner metal.

• But it's nonlinear
• the scale is different for ferrous and non-ferrous metals
• and there are different gauge standards (Brown & Sharpe, Birmingham, etc)

That being said. . .
These charts are a crucial tool for jewelers wanting to accurately convert from inches or millimeters to the equivalent gauge when purchasing and using round wire or flat sheet.

But I suggest that instead of using gauge, you follow the ASTM's suggestion and go with thickness measured in inches or millimeters instead:
"The use of gauge number is discouraged as being an archaic term of limited usefulness not having general agreement on meaning." (Specification ASTM A480-10a)

I highly recommend that you print a copy of this for your bench and your computer. This way you are always one glance away from knowing the gauge you want when you are hard at work on a piece of jewelry.

The American wire gauge (AWG) standards for wire

This table is for a single, solid, round wire.

AWG is also commonly used to specify body piercing jewelry sizes (especially smaller sizes), even when the material is not metallic.

Increasing gauge numbers denote decreasing wire diameters, which is similar to many other non-metric gauging systems such as SWG. This gauge system originated in the number of drawing operations used to produce a given gauge of wire. Very fine wire (for example, 30 gauge) required more passes through the drawing dies than 0 gauge wire did.

Below is some information about Brown & Sharpe from Wikkipedia,

During the 19th and 20th centuries, Brown & Sharpe was one of the best-known and most influential machine tool builders and was a leading manufacturer of instruments for machinists (such as micrometers and indicators). Its reputation and influence were such that its name is often considered to be inseparably paired with certain industrial standards that it helped establish, including:

• The American wire gauge (AWG) standards for wire;
• The Brown & Sharpe taper in machine tool spindle tapers; and
• The Brown & Sharpe worm threadform for worm gears.

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