The cast armor specified herein is intended for use on combat vehicles. The thickness of the casting is considered to be that which is most representative of the component's ballistic surface.

Class 1 cast armor is intended for use in those areas where maximum toughness and maximum resistance to penetration by armor piercing type of ammunition is required.

Class 2 cast armor is intended for use in those areas where maximum resistance to failure under conditions of high rates of shook loading is required and where resistance to penetration by armor piercing ammunition is of secondary importance. It is for protection against anti-tank land mines, hand grenades, bursting shell, and other blast-producing weapons.