The original idea for making chain link came from the idea of weaving wire in the way thread is woven to make cloth. This is why different chain link styles are “fabric.”
Different types of chain link fabric have different wire thickness called gauge. The larger the gauge, the less the diameter of the wire. When making wire, the tolerance in the mills is a mere plus or minus .005 inch. The largest wire used for chain link is 6 gauge which is .192 inch thick. The smallest is 12 1/2 gauge with is .009 inch thick. There are also the gauges of 9, 11, 11 1/2, and 12. Another variation in chain link fabric is the height. Chain link is available in heights of 3 feet, 3 1/2 feet, 4 feet, 5 feet, 6 feet, 7 feet, 8 feet, 10 feet and 12 feet.
Chain link fabric comes from using spirals of wire and then making a weave pattern with them. The top and bottom edge is the “selvage.” There are three types of selvage: 1) knuckled (KK); 2) knuckled mixed with barbed (KB), and; 3) and barbed (BB). Knuckled means the wire continues around without a cut so there are no sharp wire-ends exposed. The standard of the industry is to knuckle both top and bottom for fences 6 feet high or less. Heights above 6 feet may have twisted ends or barbed wire.
There are two types of zinc coating: 1) galvanized before weaving (GBW) and; 2) galvanized after weaving (GAW). GBW chain link consists of wire galvanized first, then woven and has .8 oz. or less of zinc per square foot. GAW chain link consists of regular wire, which is woven together then dipped into molten zinc. It has 1.2 oz. per square foot of zinc.
The mesh size of chain link is a measurement between two wires running parallel to each other. Most chain link has a mesh size of ether 2 inches or 2 1/4 inches. Chain link is also available in the smaller mesh sizes of 3/8 inch, 5/8 inch, 1 inch, 1 1/4 inches, 1 1/2 inches and 1 3/4 inches used for additional security.
The ASTM standard of A 392-36 gives the designation of quality, which comes from wire gauge and the weight of zinc.
The steel posts and rails used as supports to hold up the chain link fabric is the framework. The framework has three parts: 1) terminal posts for the ends, gates, and corners; 2) line posts to go between terminal posts, and; 3) the top horizontal rail, which completes the frame to hold the chain link fabric in place. The posts foundations are concrete and the rail is held in place by fittings. All the pieces have a zinc coating as well.
The zinc coating for rails and posts comes from two different methods according to the ASTM standards F669-92. The first one is “hot dip.” The process uses steel sheets cut into segments, bent into tubes which get a seam made by welding. The entire pipe goes into a bath of molten zinc so both the inside and outside gets coats of zinc. The other method is “in-line flow coat.” For this method the process paints the inside with zinc-based paint. The outside get a molten zinc coat and an extra finish of an organic coating, which is clear and protects against corrosion.
The quality of framework tubing comes from the gauge of the steel used and the type of zinc coating.