Understanding Auto Glass Terminology

Laminated Glass

Windshields use laminated glass. This safety feature consists of two glass layers sandwiching a polyvinyl butyral (PVB) interlayer. Upon impact, the PVB prevents the windshield from shattering into sharp shards. Instead, laminated glass cracks.

Tempered Glass

Side and rear windows use tempered glass, also known as safety glass. It’s processed for strength and a unique shattering pattern.

Upon impact, tempered glass crumbles into small, relatively harmless pieces. This allows for easier escape in a rollover accident. While challenging to break initially, tempered glass can theoretically explode during driving.

This is why laminated windshields are used. For more information on auto glass repair, visit auto glass repairs.

Chips, Cracks & Breaks

A “chip” is a small piece of glass missing from the windshield’s outer layer, often caused by road debris. A “ding” is another term for minor stone damage, similar to a chip.

A “crack” describes larger areas of damage in laminated glass. This includes chips, bullseyes (circular damage), or combination breaks.

These originate from the impact point and signify a broken inner PVB layer. These terms apply to laminated windshields and tempered glass in door, quarter, and back glass.

For a better understanding of these classifications and related terms, see our auto glass glossary.

The Acute Area

This critical windshield area is directly in front of the driver. Measuring 8 ½ inches high x 11 inches wide ensures proper driver vision.

In North America, this area influences repair/replacement standards and decisions at most auto glass shops and insurance companies.

The Frit

The frit is the black band around the edges of most auto glass. This baked-in ceramic paint serves both protective and aesthetic purposes.

It shields the adhesive, sealing your windshield from harmful UV rays. Auto glass experts can provide more information about faulty glass.

OEM vs. Aftermarket

OEM stands for Original Equipment Manufacturer. OEM glass comes from the same manufacturer as your original windshield, while a different supplier manufactures aftermarket glass.

For an accurate repair quote, visit our auto glass repair page.

ADAS Calibration

ADAS (Advanced Driver-Assistance Systems) includes lane departure warnings and adaptive cruise control features. After a windshield replacement, ADAS calibration is often needed.

Calibration ensures these safety systems function correctly. It is also important to maintain your vehicle’s structural integrity after a windshield replacement.

Urethane

This high-strength adhesive bonds auto glass to the vehicle frame. It has replaced older butyl technology. Urethane is essential for complying with current industry safety standards.

This powerful bond is crucial for adequately functioning your car’s auto glass. Its high modulus ensures a robust and lasting connection between the glass and frame.

SDAT (Safe Drive Away Time)

SDAT is the safe drive-away time after a windshield replacement. It varies depending on the adhesive used but is typically one hour. A qualified auto glass technician should clearly communicate this information.

Confirming the SDAT is essential before driving, whether you visit a shop, use their website chat, or receive other communications.