Types of Standard Weave Styles

	Plain Weave (double crimp) This style has a wire in every crimp it is commonly used in general screening application.
	Intermediate Crimp This weave style is basically a plain crimped wire that has the wires placed in only odd numbered crimps (the intersections occur only at odd numbered crimps. IE. 3, 5, 7, 9) This weave style is good for screening applications where the relative opening is large compared to the wire diameter.
	Lock Crimp This weave style is connected at a pre-defined location that locks the intersection into place making a tight weave that resists “racking” and gives it very accurate openings.
	Flat Top This weave style has all the crimps on one side giving the other side a smooth surface. This style also has less resistance to material flow.

Specifying Wire Mesh

Everything starts with the Mesh Centers and the Wire Diameter of a particular spec. These two dimensions are the base dimensions we use to calculate all of the other necessary information that will facilitate the correct selection of your wire cloth requirements.

With these two dimensions we can carry out further calculations that help us to:

• Produce custom tooling if needed for your requirement in house with a very high degree of accuracy.
• Help in the selection of the best weave style for a particular applications’ needs.
• Help in selecting the best opening to wire diameter relationship for sifting, sizing and flow applications.

Wire Mesh is typically called out by one of the following three criteria:

1. Mesh Centers - (C) Refers to the center of one wire to the center of the next parallel wire.
   Ex) ½” Centers
   
   
2. Mesh Opening - (O) Refers to the measureable distance between two parallel wires.
   Ex) ½” Opening
   
   
3. Mesh Count - (MC) Refers to the number of openings and fractional parts of an opening that can be counted in one lineal inch. When the point one inch distant from the center of a wire is not a whole number the Mesh Count is expressed in fractions.
   Ex) 4 Mesh, 2.5 Mesh

Mesh Count

Index

All wire mesh has mathematical Index. This Index is the relationship of the Mesh Centers to it’s  Wire Diameter. 
This relationship is expressed as:

This index is critical in the proper selection of weave styles. Generally the smallest index (2) starts with plain weave and as the index increases the many choices  of different weave styles  and patterns increases with it. Depending on your needs the range of available Mesh styles is almost unlimited. 

Percentage of Open Area

The percentage of open area in wire mesh is the ratio of the total open area of all of the Mesh openings combined relative to the entire screens area.

In Wire Mesh applications that involve a required flow rate, as in material sizing, the flow of liquid or even the luminescence of light that passes through, the Percentage of Open Area  is used to determine  which mesh specification will be best suited to a particular application. The formula (for square mesh material [same spacing in both directions] and using the same wire dimensions in both directions) the Percent Open Area is as follows:

% OA =   ( I-1)^2 / ( I )^2 * 100             Where   I = Index

To Find the Percentage of open area (%OA) for a rectangular opening find the index for each directions center distance (center distance of 2 wires ) = opening + 1 wire diameter
        
 %OA = (IL-1)^2/(IL)^2 * (IS-1)^2/(IS )^2*100        Where  IL = index of large centers        IS = index of small centers

4 x 4 Mesh .120” Wire Diameter .25” mesh centers Index =  .25/.120 = 2.083 %OA = 27.0	4 x 4 Mesh .080” Wire Diameter .25” mesh centers Index = .25/.08 = 3.125 %OA = 46.2	4 x 4 Mesh .047” Wire Diameter .25” mesh Centers Index = .25/.047 = 5.319 %OA = 65.9