Abstract: The fuze comprises a fuze body having a readily crushable nose cone and a thermal initiator, a thermally ignitable flash detonator and a main charge of booster explosive disposed in sequence in the body. The thermal initiator includes a cup having a closed front end and an open rear end closed by a non-metallic, thermally destructive closure. A readily thermally ignitable, incendiary, exothermic chemical material is disposed in the cup, and the cup is fixed in the nose. Rearward of the cup a rotor ball is disposed in the fuze, which rotor ball contains the detonator. A C-spring connects the rotor ball to the fuze body and maintains the rotor ball in an orientation such that the detonator in the rotor ball is out of alignment with the initiator except when the fuze is spinning beyond the gun barrel as when it is connected to a fired projectile. The detonator includes a cup having a closed thermal barrier alignable with the rear end of the initiator cup, and a thermally destructive closure on the opposite end.