From the fabrication standpoint, is a melt castable formulation which could be easily processed in existing high-rate loading facilities. Its explosive components are nitrotriazolone (NTO), aluminium powder and TNT, with a new wax/surfactant system, I-800/Ganex replacing the conventional D2 wax system. These inert components reduce exudation and off-gassing and enhances the TNT/wax emulsion characteristics, while improving the shock sensitivity, critical diameter and energy of the explosives.
"AFX-645 was developed by balancing energy and sensitivity requirements for surviving sympathetic detonation in the new standard metal pallet. AFX-645 blast performance measured in Mk- 82s approaches that derived from tritonal filled Mk-82s." 
- John D. Corley, Gary H. Parsons, Alan C. Stewart, Fuzed Insensitive General Purpose Bomb Containing AFX-645