The phrase toughened glass is another name for tempered glass, that which has been cooled very quickly during the manufacturing process. Toughened glass has a different composition compared to standard (annealed) glass that makes it withstand daily stresses better than annealed glass does. Once toughened (tempered) glass does break, the different tensions and compressions within the glass make it break into small pellets, rather than the large, dangerous shards into which annealed glass breaks.
Toughened Glass
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