Hardness of 9H (9H hardness 9 = corundum (sapphire) grinding hardness 1000 according to Rosiwal only the diamond is harder = 10H) Please note that this film is made of tempered real glass and a space of 1-2 mm was deliberately left to the edge of the smartphone. Since smartphone displays are slightly rounded and therefore the film cannot settle there, this distance was deliberately kept. This quenching process causes the surface to solidify and the external dimensions of the component now change only comparatively little. However, the warmer core continues to contract even more because the thermal expansion above the transformation point is significantly higher than below it. Due to this frozen prestressing, the tempered glass can compensate for significantly higher tensile loads than.
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