How to Identify the Date on Car Glass?

[ValeriaMarie]

Glass with numbers and black dots indicates the production year and month. Below is relevant information about car glass: 1. Manufacturing Process: Car glass is manufactured by heating the glass to near softening temperature in a heating furnace, then rapidly transferring it into fans with varying cooling intensities for uneven cooling. This creates different stress levels between the main viewing area and peripheral areas of the glass. Generally, glass produced this way is zone-tempered glass. 2. Classification: Car glass mainly falls into three categories: laminated glass, tempered glass, and zone-tempered glass, all capable of withstanding strong impacts. Based on location, car glass is divided into four types: windshield, side window glass, rear windshield, and sunroof glass.

[Wayne]

When I bought a used car last year, I paid special attention to the glass dates, as they are crucial for assessing the vehicle's condition. Typically, you can find markings with numbers and dots in the corners of the windshield. For example, the number 8 with three small dots next to it—dots on the right indicate production in the second half of the year, and three dots represent September. If there are two dots before the number, it means the glass was produced in February of the same year. However, be cautious—the number might represent the last digit of the year. For instance, if the car was manufactured in 2020, seeing a glass marked with '8' could mean it's an older glass from 2018. During my inspection, I once found that the rear window's date was half a year later than the others, and checking the records confirmed it was replaced after an accident. This detail can help you avoid flood-damaged cars. Always cross-check the dates on multiple glass panels to ensure consistency.

[AdalynnLynn]

Last week, I accompanied my friend to pick a car and taught him how to check the glass production date. First, look for the string of codes with dots at the bottom corner of the windshield. The number represents the last digit of the year, and the position of the dots determines whether it was produced in the first or second half of the year. For example, if there's a '7' followed by two dots, it means the glass was produced between July and August of 2017 or 2007. In practice, you need to cross-reference this with the vehicle's production date. If the glass date is later than the vehicle's production date, it's definitely been replaced later. My friend later noticed that the driver's side glass was marked as produced in March 2019, while the vehicle's nameplate showed a production date of November 2018—clearly a mismatch, so he wisely decided not to buy it. Replaced glass usually indicates an accident, and this little trick can save you a lot of money.

[Wren]

With over a decade of experience in auto repair, I frequently handle windshield replacements. The most accurate way to check the glass production date is by looking at the dot markings in the corner. For example, a dot before the number 6 indicates production in January of the first half of the year. Dots before the number represent January to June, while dots after signify July to December, with the number of dots corresponding to the specific month. Once, a customer came in for a windshield replacement, and the new glass was marked as produced in August 2023, two years newer than the original factory date. I immediately recognized it as an aftermarket part. Original factory glass dates should closely match the vehicle's production date, with a discrepancy of no more than three months. When replacing glass, it's crucial to verify the date to ensure proper sealing and driving safety.

[EdenRose]

Just learned how to read glass dates and I'm super excited! Simply find the string of symbols in the corner of the window: the decimal point represents the month, and the number is the last digit of the year. For example, seeing '.5' means it was produced in the 5th month of either 2015 or the first half of 2005. I compared the four pieces of glass on my car and found that the sunroof was produced in April 2020 (four dots before the number 0), while the others were all from November 2019 (five dots after the number 9). An experienced driver told me that such differences indicate the sunroof was replaced, and sure enough, when I asked the 4S shop, there was a maintenance record. Now, every time I wash the car, I habitually glance at the date markings—it only takes three minutes to get a preliminary assessment of the car's condition.

[PaisleyAnn]

I found the glass date extremely practical when researching vehicle information. The combination of black dots and numbers on the edge of the windshield, such as the number 8 followed by four dots, indicates production in October 2018 (the fourth dot after represents October). The most interesting part is that different brands have different marking positions—Japanese cars often place it in the lower right corner, while German cars prefer the lower left. Last time I checked a used car, the dates on the four door glasses spanned two years, clearly indicating a pieced-together accident vehicle. It's recommended to cross-check with the vehicle's VIN code and factory production time, with a discrepancy of up to six months considered normal. These small markings hold significant information, and understanding them can help avoid pitfalls.