Views: 5 Author: Site Editor Publish Time: 2018-05-14 Origin: Site
KNOWLEDGE:
To help you develop a good working knowledge of the various types of wire mesh, perforated metal and expanded available on the market as well as understanding how the material is manufactured and specified.
If you have any questions about the products, specifications or terminology, please contact us.
Centres
Commonly used to describe perforated metal hole spacing e.g. 1/4” dia holes x 3/8” staggered centres means the 1/4” dia holes are spaced 3/8” from the centre of one hole to the centre of the next hole. Determines the % open area i.e. the closer the holes are together the higher the % open area. When used to describe mesh, it is the distance from the centre of one wire to the centre of the next wire.
Crimp
Knuckles or bumps in the wire that keep the wires in position. When both warp and shute wires are crimped it is known as double crimp.
Galvanized after welding (GAW)
Welded wire mesh is made out of mild steel (plain steel) wire. The welded wire mesh is then hot dip galvanized in order to completely coat it. Galvanizing welded wire mesh after the welding process offers better corrosion resistance but is typically more expensive than GBW (see below).
Intercrimp or intermediate crimp
Extra crimp in wires between points of intersection (between wires). Usually only available on 1/2 x 1/2 mesh and coarser.
Market grade woven wire mesh
A family of mesh with heavier wire diameters than tensile bolting cloth for more strength and typically for industrial filtering applications.
Percent open area
The percent open area in mesh and perforated relates to the amount of flow that will go through the mesh or perforated. The higher the percentage of open area, the more something will flow through the mesh or perforated. Another way to think about it is if a product has 40% open area, it means that 60% of that product is metal or solid. You can have mesh with small holes that has a larger percent open area than mesh with larger holes e.g. a 20 x 20 mesh x .016” dia wire has a .034” x .034” square clear opening with 46.2% open area and a 6 x 6 mesh x .062” dia wire has a .104” x .104” square clear opening (much larger holes) with a 38.9% open area (smaller open area).
Mathematically (for square mesh) it is mesh count squared multiplied by clear opening squared multiplied by 100 e.g. the percent opening of a 20 x 20 mesh x .016” dia wire is: 20^2 x .034^2 x 100 = 46.24% open area.
Mesh count (from 1 to 635):