>>10325005Tempered glass generally does not break that way. It's built to take small impacts like that, the superheating process that produces tempered glass bonds the molecules very tightly and gives it great durability, scratch resistance, and adaptability to temp fluctuations.
Despite its relative strength in something like a sudden impact, tempered glass has some "Achilles heel" style weaknesses. Part of the process of producing it compresses it, with its tension in perfect balance. If that tension is disturbed, by something like a small nick or chip in an edge, it can spiderweb outward and cause the entire pane to fail. Small chips and nicks are really tough to notice, so this is why many people think their tempered glass "suddenly just exploded."
