Definitions & Formulae

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Definitions and Formulae

Aperture (w)

Space between adjacent parallel wires, in mm.
(25.4 / n) – d

Wire Diameter (d)

Diameter of wire before weaving, in mm.

Mesh Count (n)

Number of apertures per lineal inch measured from the centre of one wire to a point 1 inch (25.4 mm) distant.
25.4 / (w + d)

Pitch (p)

Distance between the centres of two adjacent wires in mm.
w + d or 25.4 / n


Wires running lengthwise in the cloth as woven.


Wires running crosswise in the cloth as woven.

Open Area %

The fractional open surface area of the wirecloth in the flow direction
(w²) / (w + d)² * 100 (applicable for square meshes only).


The fractional void volume of the mesh.