There are many different wire gauges in use in North America. The two most common are:
British Standard Wire Gauge - SWG (a.k.a. British Imperial Standard)
American Standard Wire Gauge - AWG (a.k.a. Brown & Sharpe)

Websters Revised Unabridged Dictionary 1913 states (under "wire"): "Wire gauge or gage. (a) A gauge for measuring the diameter of wire, thickness of sheet metal, etc., often consisting of a metal plate with a series of notches of various widths in its edge. (b) A standard series of sizes arbitrarily indicated, as by numbers, to which the diameter of wire or the thickness of sheet metal is usually made, and which is used in describing the size or thickness. There are many different standards for wire gauges, as in different countries, or for different kinds of metal, the Birmingham wire gauges and the American wire gauge being often used and designated by the abbreviations B. W. G. and A. W. G. respectively."

Why are there two different Standards? In the 1850's ... "The brass business of Connecticut, centered in the Naugatuck Valley, required sheet metal and wire gages for measuring their products. Mr. Sharpe, with his methodical mind, conceived the idea of producing sizes of wire in a regular progression, choosing a geometric series as best adapted to these needs. Such gages as were in use prior to this time were the product of English manufacture and were very irregular in their sizes."

In AWG, the thickness (gauge) of the wire decreases by 10.9% and the area decreases by 20.7% for each gauge step. In SWG, there doesn't appear to be any logic. It's probably based more in tradition than in arithmetic.

The trouble is that right between 18 and 12 gauge, These two standards are almost, but not quite, exactly 2 gauge sizes different. For our Chainmaille purposes, 12 gauge AWG is the same as 14 gauge SWG (between 18 and 20, they are 1 size different) Take a look at the table below.

For a more complete listing, Click here.


Back to my brass and copper wire. I found the original packaging for all the wire I've purchased. Hmmm. They only say "Gauge," not AWG or SWG. So what do I have? I set out to measure the diameter of the wire. Luckily, in my "weird" toolbox of strange tools that my father left me, I found an old "American Standard Wire Gauge". ( I always thought it was a drill index!) On one side it shows the AWG gauge sizes and on the other it has the diameter in inches. My 14 gauge galvanized steel wire measured 12 AWG; my 16 gauge galvanized steel wire measured 14 AWG; my 16 gauge copper and brass wire measured 16 AWG.

Conclusion to my dilemma:
The Galvanized Steel was measured in SWG and the Copper and Bronze were measured in AWG, hence the size differences. Even though all of my wire came from the same company in Tennessee, they are using two different gauges. This is an acceptable practice. You see, AWG was intended for Non-Ferrous metals only!

It turns out that every single person who tried to give me a reason for my size difference was correct! Nobody was wrong.