Wire mesh comes in hundreds of sizes, and it is complicated to choose the desired size. The most important thing to remember is the spacing-opening-diameter relationships: spacing equals wire diameter plus opening size, opening size equals wire spacing minus wire diameter and wire diameter equals wire spacing minus opening size.
Wire spacing, which is also called mesh spacing, is a measured distance expressed in inches, and it is important to be careful with this component. Many buyers confuse 2 mesh, which is 1/2 inch on centers, and 2-inch mesh, or 2 inches on centers. This can make a huge difference when installing the mesh.
Industrial specifications are usually made with round cross-section wire. When choosing this type of mesh, it's easiest to refer to the wire diameter in fractions of an inch instead of gauge. Standard wire diameters range from 0.035 to 0.375. Other factors in choosing mesh include percent open area and mesh to diameter ratios, aspect ratio and apparent percent open area.
With all of the complex variations in wire mesh, it is often best to consult a professional when purchasing to ensure the proper purchase. Sales clerks at local hardware stores or big box stores such as Home Depot are very helpful in this capacity. If the job is significantly complex, wire experts are also available at specialized store locations.