The short answer is that nobody “cuts” windshields. They are manufactured in the shape and size to fit certain vehicles. There are more than 35,000 different sized and shaped windshields in Northern America, each designed to fit a unique make and model of vehicle.
Properly manufactured and installed windshields can be crucial. Have you ever been in a crash? Think about the force with which the airbags go off. The auto glass in your car is part of the passenger restraint safety system. If, for example, the windshield isn’t manufactured properly or installed correctly, your life could be on the line.
Laminated vs. Tempered Auto Glass
Most vehicles sport two different types of glass: laminated and tempered. Most windshields are made of laminated glass and most of the other glass is most likely tempered. Both types of glass require a higher amount of pressure per square inch to break than regular annealed does. Each has additional properties as well.
The next time your windshield breaks and you need a replacement, ask the automotive glass technician which manufacturer made your glass. This information should also be available right on your new glass. Every windshield has a unique number etched into the corner, called the DOT number, that tells you which company manufactured the glass. You can look up which company made your glass by using this DOT Look-Up Tool (go to the DOT Look Up on the right side of the page).