Amatol was developed by the British in World War I as a way of conserving their meager TNT supplies. It is composed of AN (Ammonium Nitrate) and TNT (Trinitrotoluene) in varying ratios, the most common being 80/20. It is slightly more efficient than TNT when used in breaching charges, but since it contains AN it is somewhat hygroscopic and must be well sealed against moisture.  Amatol has a detonation velocity of 16,000 feet per second, almost twice that of straight AN.  amatol is very insensitive, and while this makes it safe to handle (in fact, the blocks can be cut up with a hand saw), it can also make it harder to detonate.  Amatol production is an excellent way of stretching an explosives supply.  Amatol is not as safe to make as some other high explosives since it uses molten  (shock-sensitive) TNT.