Glass Surface Quality – Scratch/Dig Specifications
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 upon industry standards. The lower the ratio, the more stringent the specification.
Your specific application will determine the quality level and test procedures necessary. Specifically, this specification defines the state of polish, and freedom from scratches and digs.
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. See Standards Table below. Keep in mind that this equivalence is determined purely by visual comparison, and the appearance of a scratch can depend upon the component material, 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. The diameter of an irregularly shaped dig is ½ x (Length + Width).
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
- 40/20 laser quality
- 20/10 optics precision
Abrisa Technologies has a specific standard AS1001 for performing scratch/dig inspection. To view this specification – click here.
Abrisa Technologies is a recognized global supplier of high quality, fabricated glass components, optical thin film coatings, and custom glass solutions for a wide variety of industries. From our US based Abrisa Industrial Glass fabrication facility in Santa Paula, CA and our ZC&R Coatings for Optics division in Torrance, CA we serve diverse industries such as microelectronics and displays, semiconductor, military, automotive, aerospace, medical, biomedical and scientific R&D. We provide custom specialty flat glass and coating products for applications such as: flat panel display, touch and gesture recognition; visible to IR imaging and surveillance; entertainment, indoor and outdoor lighting; advanced instrumentation; and photonics.