Shot blasting machines with continuous horizontal conveyor belt represents a versatile solution particularly suitable with iron and aluminium, for the treatment of those pieces that, for reasons of shape or delicateness, cannot be subjected to treatment in a traditional conveyor-belt shot blasting machine.The turbines (4 or 8 in number, according to the complexity of the items to be treated) are positioned both above and below, thus allowing optimum treatment in a single treatment cycle.