SIST ISO 7806:1999 PDF

The perforation of a plate is designated by 1: shape of the holes, 2. aperture size, 3. mutual arrangement of holes, 4. pitch, 5. orientation of the arrangement of the perforations relative to the edges of the plate. The code expresses the items of designation by symbols and magnitudes in the sequence above. The standard applies to perforated plates regardless of the plate material.