W.A. Wilson Glass Plus
A Reflection of Quality & Service
Follow Us:
Glass Inspection Standards
W.A. Wilson fabricates high quality tempered, insulated, and edged glass products. Any flaws that develop as a result of the manufacturing or handling process are inspected using the Glass Industry Standards ASTM C1036 for Flat Glass, ASTM C1048 for Heat Treated Glass, ASTM C1376 for Low-E Coatings on Flat Glass, ASTM C 1651 Roll Wave Optical Distortion for Heat Treated Glass, and ASTM C 1503 for Mirrors.
All of these documents are copyrighted and available for purchase at www.astm.org.
Dimensional Tolerances For Rectangles
| Thickness Range in Inches | Length and Width Tolerance | ||
| Glass Thickness | (min-max) | Cut Size | Stock Sheet |
| 2.5 MM (Single Strength) | 0.085 – .0101 | 1/16″ | 1/4″ |
| 3.0 MM (Double Strength) | 0.115 – 0.134 | 1/16″ | 1/4″ |
| 5.0 MM (3/16″ Glass) | 0.180-0.199 | 1/16″ | 1/4″ |
| 6.0MM (1/4″ Glass) | 0.219 – 0.244 | 1/16″ | 1/4″ |
| 10MM (3/8″ Glass) | 0.355 – 0.406 | 3/32″ | 1/4″ |
| 12MM (1/2″ Glass) | 0.0469 – 0.531 | 1/8″ | 1/4″ |
Surface Imperfections
All inspections are done with the viewing angle at 90 degrees to the glass surface, uniform diffused lighting that stimulates daylight, and with the inspector looking thru rather than at the glass surface.
Architectural glass that is produced as annealed, tempered, non Low-E insulated, or laminated
Scratches and Rubs
The inspector begins the inspection by standing at a distance of 160” from the glass surface. The inspector then moves closer to the glass surface, stopping at the point where the scratch or rub is first detected. If this distance is between 160” and 132” then it cause for rejection. If the scratch or rub is visible when viewed between 132” and 40” and is over 3” long it is cause for rejection. If the scratch or rub is visible when viewed between 132” and 40” and it is less than 3” long, it is allowed as long as it is separated from a similar scratch or rub by at least 24”. If you need to be closer than 40” from the glass surface to view the scratch or rub, then it is allowed.
Bubbles, Pits, Knots, and Dirt
With the inspector standing at 39” from the glass surface, and the glass thickness is ¼” or less, bubbles, pits, knots, or dirt is allowed if the average of blemish’s length and width is 1/16” or less. Blemishes with an average length and width of 3/32” are allowed if they are separated from a similar blemish by at least 24”. Bubbles, pits, knots and dirt is not allowed if their average length and width exceeds 3/32.”
Edge Chips
DEPTH- measuring from the face of the glass a chip is allowed if it’s depth does not exceed more than 50% of the glass thickness
- WIDTH- measuring the perpendicular distance from the edge of the glass to the inner edge of the chip, a chip is allowed up to half of the glass thickness or ¼”, whichever is greater; for mirrors up to half of the mirror thickness or 1/16”, whichever is greater.
- LENGTH- measuring parallel from the edge of the glass to the edge of a chip, a chip is allowed if its length does not exceed two times its width.
Architectural glass coated using a hard or soft coat low-E process.
Maximum Bow and Warp Tolerances
Scratches and Rubs
The inspector begins the inspection by standing at a distance of 120” from the glass surface. The inspector then moves closer to the glass surface, stopping at the point where the scratch or rub is first detected. If the scratch or rub is visible at a distance of 120”, is over 3” long, and is located in the central viewing area (defined as 80% of the length and 80% of the width dimensions centered on the lite of glass) then it is cause for rejection.
Coating Pinholes
Coating pinholes greater than 1/16” of an inch are not allowed. Pinholes less than 1/16” in diameter are allowed if they are located outside of the central viewing area. At a distance of 120” from the glass surface, three or more pinholes greater than 3/64” in size are not allowed if they are located within a 6” diameter cluster of one another.
Coloration
Low-e coated glass may exhibit a hue or coloration that is not apparent in architectural samples, especially in shaded or darkened light or when viewed at a glancing angle. This coloration is inherent to the coating process and is not a reason for rejection.
Spandrel Glass
All inspections are done with the viewing angle at 90 degrees to the glass surface, standing outside the building, and at a distance of 180” from the glass surface. Spandrel glass is not intended to be viewed from the interior.
Color and reflectance may vary when viewed under a uniform, opaque background. This is not considered a defect.
Heat Treated Glass
Glass Distortion
Maximum Bow and Warp Tolerances
| Glass Thickness | |||||
| Edge Dimensions | 1/8″ | 3/16″ | 1/4″ | 3/8″ | 1/2″ |
| 0-20″ | 5/64″ | 1/8″ | 5/64″ | 5/64″ | 5/64″ |
| >20″ – 35″ | 5/64″ | 5/32″ | 1/8″ | 5/64″ | 5/64″ |
| >35″ – 47″ | 5/64″ | 13/64″ | 5/32″ | 5/64″ | 5/64″ |
| >47″ – 59″ | 1/8″ | 9/32″ | 13/64″ | 13/64″ | 5/64″ |
| >59″ – 71″ | 13/64″ | 11/32″ | 9/32″ | 13/64″ | 5/32″ |
| >71″ – 83″ | 15/32″ | 15/32″ | 11/32″ | 15/64″ | 13/64″ |
| >83″ – 94″ | 9/32″ | 17/32″ | 15/32″ | 9/32″ | 13/64″ |
| >94″ – 106″ | 21/32″ | 17/32″ | 11/32″ | 9/32″ | |
| >106″ – 118″ | 3/4″ | 21/32″ | 15/32″ | 3/8″ | |
| >118″ – 130″ | 3/4″ | 9/16″ | 15/32″ | ||
| >130″ – 144″ | 13/16″ | 21/32″ | 17/32″ |
Cut Sized Mirrors
Scratches and Rubs
The inspector begins the inspection by standing at a distance of 60’from the mirror surface. The inspector then moves closer to the glass surface, stopping at the point where the scratch or rub is first detected. If this distance is between 60” and 24” then it cause for rejection. If the scratch or rub is visible when viewed between 24” and 8” and it is less than 3” long, it is allowed as long as it is separated from a similar scratch or rub by at least 24”. If you need to be closer than 8” from the mirror surface to view the scratch or rub, then it is allowed.
Our Products
