MIL-A-12560 is a military specification that covers high-strength armor plate. The specification sets forth the requirements for ballistic-resistant steel plate intended for use in the construction of military combat vehicles, tanks and personnel carriers. 

MIL-A-46100 steel plate is designed to provide enhanced protection against ballistic and explosive threats.  The specification defines the requirements for MIL-A-46100 steel plate in terms of hardness, chemical composition, mechanical properties, and ballistic performance. The plate is typically produced through a quenching and tempering process to achieve the desired hardness and strength properties.