Abstract: This machine is more particularly designed to make a series of slits across the external surface of a tire rethread band. The band is moved step-by-step by a conveyor belt; a guillotine-type blade is reciprocated up-and-down over the band supported by the conveyor belt and effects a slit in the band when the conveyor is stopped; the depth of the slits can be adjusted; the inclination of the slits with respect to the longitudinal axis of the band can be varied; the distance between the slits can be adjusted by varying the stroke of the belt advancing mechanism; the conveyor belt has an outer anti-skid surface and the tire rethread band is applied against the same by spring-biased pressure rollers which accommodate tire rethread bands of various thicknesses.