The size of the holes are always indicated in combination with a pattern or stitch. An example of a pattern is the equilateral stitch. This is the most common pattern for filters and strainers. This stitch is designed in an isosceles triangle. The most common is R2T3 or R3T5. The diameter of the holes are 3 mm and the center to center distance is 5 mm.
- R = diameter of the hole in mm;
- T = stitch or center to center distance in mm.