How to Identify the Manufacturing Date from Car Glass?

[SawyerLynn]

The method to identify the manufacturing date from car glass is as follows: There will be a trademark in the corner of the car glass, consisting of several dots and a number. The number represents the production year of the car glass. If the dots are on the left, it indicates the first half of the year, while dots on the right represent the second half of the year. The production of car glass involves heating the glass in a furnace to near its softening temperature, then rapidly transferring it to air 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, such glass is zone-tempered glass. The peripheral areas are located in the strong air flow positions of the grids, requiring full tempering, resulting in good fragmentation and high tempering strength. The main viewing area is in the weak cooling position of the grid, leading to larger fragments and lower tempering strength.