What could cause tempered glass to break?
Tempered glass has been carefully engineered to provide strong and durable protection for your iPhone screen. Compared to ordinary glass of the same density, tempered glass can withstand 3 to 5 times harder impacts. Therefore, your screen protector provides the best protection against any drops, scratches, and everyday wear and tear. In the unlikely event that a force is too strong or your phone is dropped at an unusual angle, the screen protector may break as it absorbs the shock and diverts it away from the screen.