Percent open area is the ratio of hole area to total screen area at a 90° angle of incidence to the plane of the material, expressed as a percentage. Material with 40% open area will have 40 square inches of opening for every 100 square inches of material. Percent open area helps in comparing various materials as to how readily a product, whether it be corn, air, or light, will pass through the screen.
Mesh to Diameter ratio MD is the mesh spacing (center to center) divided by the wire diameter. We find this a very useful relationship. The MD can be used to determine appropriate crimp styles, and percent open area.
For square mesh material (same spacing in both directions) and using the same wire dimensions in both directions, the Percent Open Area is: