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Last Edited: December 11, 2012, 6:17 am
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Wire Gauges: An Overview
Article © MAIL User: Vacacita
By Theresa Olin (Vacacita)
Wire thickness is an important consideration in working with chainmaille. The size of the wire affects how delicate or bulky a piece of maille looks, how well it functions as armor, and how easy it is to work with the rings (among other things). Wire thickness is given along with inner diameter to indicate a ring size, which in turn determines aspect ratio. When discussing issues related to wire thickness, ring size, or aspect ratio, it is important to understand how wire thickness is expressed.
The clearest way to give a wire thickness is to state the actual diameter of the wire, in millimeters or decimals of inches. This can be measured with calipers. Gauge numbers are often used as a common point of reference, and most suppliers of wire and rings give gauges instead of (or in addition to) actual diameter measurements. This can become a tricky issue, since there are several different systems for designating wire gauge.
Two of the most common gauge systems are AWG (American Wire Gauge, also known as Browne & Sharpe) and SWG (Imperial Standard Wire Gauge). In both systems, a higher gauge means smaller wire.
The AWG system was developed in America to be used for electrical applications, and is still used for non-ferrous wire. (Ferrous means iron-based.) The gauge numbers are based on electrical resistance, which increases as the wire gets thinner. (Picture the electrons flowing through the wire as a bunch of people running down a hallway. If the wire/hallway gets thinner, it slows them down since there's not as much room for them to get through. That's what resistance is.) When the gauge number increases by 3, the higher (thinner) wire will have twice the resistance of the lower (thicker) wire. A general rule of thumb says that when the gauge goes up by 6, the wire diameter is halved. (So, for example, 22g would be roughly half as thick as 16g.)
SWG is a British system widely used in Great Britain and Canada, and used in the US for many ferrous metals and non-electrical applications. Gauge numbers are based on the number of times the wire had to be pulled through an Imperial standard draw plate to reduce it to the desired diameter. (A draw plate is a block or plate with a series of holes decreasing in size; pulling the wire through successively smaller holes makes it longer and thinner.) The smaller the wire, the more times it has to be drawn, and the higher the gauge.
Other systems include US Steel Wire (also known as Washburn & Moen or Roebling Gauge), which is used by steel manufacturers and is close to SWG, but not an exact match; Birmingham (or Stubs) Iron Gauge, used for iron; and Music Wire, in which the wire thickness increases with increasing gauge number. Also note that most welding suppliers give exact wire diameter rather than gauges.
The system used depends partly on location, the kind of metal, and what a person or supplier is most familiar with. The important thing is to be clear on which system is being used in any given discussion. Especially when dealing with suppliers, you want to be sure that what you get is what you expect to get.
AWG vs. SWG
In general, the same gauge number will mean a smaller wire diameter with AWG than with SWG. For example, 16g AWG is 0.0508" and 16g SWG is 0.064". That might not seem like a huge difference, but it's significant at that scale.
You can estimate a conversion between AWG and SWG as follows:
|AWG||Dia. (in.)||-->||SWG||Dia. (in.)|
Info Sources and Related Links
MAIL Glossary - See entries for AWG and SWG.
SWG - AWG - Metric by Mjodvitnir - For both AWG and SWG, you can look up the wire diameter in inches and millimeters. Note that commas are used in place of decimal points.
Wire Gauges by Spyderbeak - Discusses five different systems, with a measurement chart.
Original URL: http://www.mailleartisans.org/articles/articledisplay.php?key=322