Scratch/Dig refers to cosmetic defects found in glass from the manufacturing and/or handling process. Abrisa Technologies’ standard metric for measuring such defects is based on industry standards. The lower the ratio, the more stringent the specification.
Scratches – A scratch is defined as any linear “tearing” of the surface of the glass. The scratch number refers to the width of the reference scratch.
Keep in mind that this equivalence is determined purely by visual comparison, and the appearance of a scratch can depend upon the component material, the presence of any coatings, and lighting conditions. This, again, refers to the width. The acceptance/rejection of the length of a specified scratch is determined by a ratio of the length of the scratch to the size of the glass part.
Digs – A dig is defined as a pit or small crater on the surface of the glass. Digs are defined by their diameter. The dig number represents the actual size of the dig in hundredths of a millimeter.
Scratches are determined by width size while digs are determined by diameter.
Scratch/Dig Standards Table:
Scratch/Dig Grade Scratch Max. Width Dig Max. Diameter
120/80 0.0047” or (0.12mm) 0.0315” or (0.80mm)
80/50 0.0032” or (0.08mm) 0.0197” or (0.50mm)
60/40 0.0024” or (0.06mm) 0.0157” or (0.40mm)
120/80 is considered commercial quality
80/50 is a common acceptable cosmetic standard
60/40 is acceptable for most scientific research applications
