How to Identify the Date of Automotive Glass?
3 Answers
Methods to identify the date of automotive glass: You can check the lower left corner of the glass, which consists of graphics, numbers, and English letters, including certification marks, glass type, production date, and other information. The numbers represent the year, and there are two rows of dots to the right of the numbers. The first row of dots represents the month, and the second row consists of two different shapes of dots. The first type of dot: one dot represents N days, two dots represent N plus 10 days, and three dots represent N plus 20 days. Automotive glass mainly falls into the following three categories: laminated glass, tempered glass, and zone-tempered glass, which can withstand strong impact forces. Automotive glass is divided into four types based on its location: windshield, side window glass, rear windshield, and sunroof glass.
Every time I help a friend inspect their car's glass, I always start by looking for the small markings in the corners. It's usually a combination of numbers and dots—the numbers represent the year (e.g., '18' means 2018), and the dots indicate the specific day (e.g., three dots stand for the 21st). Details matter—use your phone's flashlight to carefully examine the edges of the glass, and don’t overlook the darker corners. The date code helps determine if it's original factory glass, as aftermarket glass might have blurry or misaligned codes. This is crucial when replacing glass, as poor fit can lead to leaks, wind noise, or even safety risks in an accident. I’ve seen cases where fake glass had incorrect dates and caused issues within weeks. Remember, the original glass date should be close to the vehicle’s manufacturing date—always check this before buying a used car.
As an ordinary car owner, I learned a simple trick when replacing my windshield last time. Look for the combination of numbers and dots in those small imprints at the corners of the glass. The numbers represent the year - for example, 20 before or after the dot means 2020. The number of dots indicates the month, such as two dots representing February. It's quite straightforward in practice; just bring a good magnifying glass and examine it under strong light. This technique is especially useful when buying used cars, as a windshield replaced after an accident with a suspiciously recent date is a red flag. I also remind everyone to regularly check their windshield condition. Replace damaged glass immediately with products from authorized shops to avoid potential hazards later, like dangerous high-speed shattering.
