US Patent 9604876 Glass sheet

A glass sheet, the thickness of which is at most 2 mm, including a surface zone under compression and a central zone under tension, such that the depth at which the transition between compression and tension occurs is at least 100 micrometers, the ratio between the depth and the thickness being at least 0.1, the sheet additionally being such that the flexural stress at break in a “ring-on-tripod” test is at least 70 MPa, after Vickers indentation under a load of 60 N.