What Information Can Be Found on Car Glass?
3 Answers
Domestic car glass markings can be divided into four categories: national safety certification marks, foreign certification marks, car manufacturer marks, and glass manufacturer marks. The following information can be identified: 1. Safety Certification: Automotive safety glass is a mandatory national certification product, so every piece of glass on a car should have the national safety certification mark, commonly known as the "Square and Circle Mark," which is the most common and important mark on car glass. Other marks include foreign certification marks, such as the U.S. "DOT" mark and the European ECE "E" mark, indicating that the product has also been certified by these foreign certification bodies and can be exported abroad. 2. Production Date: The VIN (Vehicle Identification Number) located below the windshield reveals the car's production date. The tenth digit of the VIN indicates the production year of the car. The numbers represent the year of glass production, while the small dots in the first row represent the month of that year, with a minimum of 1 dot and a maximum of 12 dots. The second row represents the corresponding days of the month, with large dots indicating 10 days and small dots indicating 1 day.
As a veteran driver with over a decade of experience, I've come to see the windshield as a faithful recorder of daily driving. The tiny codes in the corners, when examined closely, reveal the production year and manufacturer—like the dot-matrix numbers indicating the year, helping assess if the vehicle is too old and needs maintenance. During city drives, the fine scratches left by wipers hint at poor wiper quality or delayed replacement. If blurry patches appear, it's likely due to aging UV coatings failing, signaling prolonged sun exposure and the need for a check-up. Additionally, the location and depth of small pits from stone impacts can infer road conditions—central pits often mean highway gravel, reminding me to slow down. The glass also reveals safety info: edge certifications like 3C or E-mark confirm crash-test compliance, ensuring road safety. In short, closely observing windshield conditions helps prevent issues early and avoid costly repairs.
I often help out at the auto repair shop, and I can diagnose vehicle issues just from the glass information. With a quick glance at the inscriptions on the edges of the windshield, I can immediately determine the manufacturing date and model, distinguish between OEM and aftermarket parts, and avoid the pitfalls of refurbished cars. The subtle patterns of cracks are treasure troves of clues: horizontal cracks often start at the corners, usually caused by drastic temperature changes or impacts; vertical cracks are mostly caused by stone impacts, and their central positions indicate excessive speed. Bubbles or peeling coatings on the glass expose issues with adhesive quality, indicating material aging and the need for replacement—otherwise, fogging in rainy weather becomes a hazard. For example, residual debris and repair marks can reconstruct accident scenes, such as radial cracks pointing to the impact site, aiding in liability determination. In short, combining this information makes repairs faster and more accurate, saving time and effort.
