Abstract: An air-blasting cartridge comrises a housing (1) subdivided into an inlet chamber (3) and a discharge chamber (4) by a piston (2) arranged along its longitudinal axis. The inlet chamber (3) communicates with a source of compressed air through an air admission tube (6) which runs through an axial port of the piston (2). The discharge chamber (4) communicates with the inlet chamber (3) through an annular gap (7) between the air admission tube (6) and the piston (2). The discharge chamber (4) is adapted to communicate with the surrounding atmosphere at the instant of its discharge. The area of the piston end surface (10) facing the discharge chamber (4) is greater than the area of the piston end surface (11) facing the inlet chamber (3) but is smaller than the area of the end surface (12) of the collar (8) on the piston (2) that faces the discharge chamber (4), said collar forming, together with the housing (1), an additional chamber (9) on the side facing the inlet chamber (3).