How to Determine the Production Date from Car Glass?
1 Answers
The method to determine the production date from car glass is as follows: It is represented in the form of numbers plus dots. The dots can be either in front of or behind the numbers. The way to read this representation is simple: the number indicates the year, and the dots indicate the month. If the dots are in front of the number, it represents the first half of the year. Subtract the number of dots in front of the number from 7 to get the month in the first half of the year. If the dots are behind the number, it represents the second half of the year. Subtract the number of dots behind the number from 13 to get the month in the second half of the year. Another representation is numbers plus small dots plus large dots. Here, the number represents the year, the small dots represent the quarter (there are 4 quarters in a year, so there are usually 4 small dots), and the large dots represent the month within the quarter (a quarter has 3 months, so there are usually 3 large dots). Car glass is manufactured by heating the glass in a furnace to near its softening temperature, then quickly transferring it to cooling grids with different cooling intensities for uneven cooling. This creates different stress levels between the main viewing area and the peripheral areas of the glass. Generally, this type of production results in regional tempered glass.
