Degree of hardness of 9H (9H degree of hardness 9 = corundum (sapphire) grinding hardness 1000 according to Rosiwal only the diamond is harder = 10H) Please note that this film is made of hardened real glass and 1-2 mm of space was deliberately left at the edge of the smartphone. Tempered glass is a type of glass in which mechanical stresses are specifically generated in the material through heat treatment However, the warmer core continues to contract even more, since thermal expansion is significantly higher above the transformation point than below. Due to this frozen prestress, the tempered glass can compensate significantly higher tensile loads than untreated glass. Since the compressive strength of glass significantly exceeds the tensile strength, this represents an overall improv.
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