Spontaneous breakage of tempered glass is most commonly caused by chipped or nicked edges during installation, stress caused by binding in the frame, internal defects such as nickel sulfide inclusions, thermal stresses in the glass, and inadequate thickness to resist high wind loads.
Does tempered glass shatter easily?
Although tempered glasses don't easily break. The impact can break it. For example, a tempered screen protector can handle low drops. But dropping it from a higher altitude and with more force tends to create cracks and scratches.
What does it take to shatter tempered glass?
According to the stress required to break tempered glass is about 24,000 psi. ... The force necessary to exceed the 24,000 psi strength of the glass is 25,000*0.0025 or 60 pounds of force. If the object is much smaller, obviously a much smaller force is needed to break the glass.