 The stopping power of glass exceeds that of steel armour on a thickness basis and in many cases glass is more than twice as effective as steel on a thickness basis.Although the T95 never entered production, a number of its concepts were used on the M60 Patton, and during the development stage (as the XM60) the siliceous-cored armour was at least considered for use, although it was not a feature of the production vehicles.The first widespread use of a composite armour appears to have been on the Soviet T-64.