Strict standards are applicable to the classification of armoured glass in burglary protection.
The European standard for burglar-proof glazing (EN 356) distinguishes three resistance classes.
If e.g. 31 strikes are enough to produce the required opening measuring 40 x 40 cm, the armoured glass is allocated to the lowest resistance class P6B; from 71 strikes upwards it receives the resistance class P8B.
