6x6 W1.4/1.4 is a designated mesh size. The "6x6" is the horizontal and vertical spacing of the strands in inches. This is the size of the squares of space bounded by the wire strands in the mesh (the equivalent in metric is in millimeters and so 6x6 inches is 152 x 152 mm). The "1.4/1.4" is the "W" number. This is the wire size (longitudinal/transverse) in cross sectional area measured in 1/100's of a square inch (1.4 hundredths of a square inch).

(the equivalent in metric is in square millimeters and so 1.4 hundredths of a square inch is 9.1 mm²)

In times gone by, the wire size was given in gauge rather than in cross sectional area by hundredths of a square inch. What is now called 6x6 W1.4/1.4 used to be called 6x6 W10/10.

"MW" is for "Metric W number"

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