Bullet Proof glass is a glass construction designed to stay intact and secure under the force of a bullet, protecting internal occupants and objects.
This high security glazing is achieved by layering different panels of glass together with interlayers such as a PVB or Sentry laminates, creating thick glass panels that can withstand the strength of a fired projectile. Generally the top surfaces of glazing are designed to break and slow down the projectile whilst the inner panes of the laminated unit absorb the pressure and stop the bullet from entering the space.
Bullet proof glass has two main objectives; one, to stop bullets and projectiles from entering a space through the glass and two, to reduce or stop any glass fragments from being spread or blown into the internal space under fire. This glass fragment spread is referred to as spawl and excessive spawl can harm internal surfaces or occupants.
The class of bullet resistant glass is tested using the EN regulation 1063. This test gives a standardised security rating applicable to all bullet proof glazing. It is classed and tested in accordance to what type of weapon and ammunition the glass units can protect against. The test classes range from BR1 for a rifle with round nosed lead bullets up to BR7 for a rifle with steel hard core ammunition. Shotgun protection classes are rated separately with a testing class of SG1 or SG2.
These security ratings only refer to the glass and for a full security rating for a window, door or installation the framing and installation will also need to be considered.
You will need to determine what type of bullet protection you need in order to specify the glass required.