Abstract: A transportable machine reduces vehicle tires to a fine powder size suitable for incorporation into new articles of manufacture. An upper infeed assembly is mounted to a frame above a spring-loaded upwardly biased lower infeed assembly. A splayed tire is fed between guiderails on the upper and lower guide assembles and is driven along by upper drive sprockets and rides on lower idler sprockets. The tire is fed by a tire-feed positioned above a cutter bar and biased downwardly to clamp a cut splayed tire against the cutter bar and to feed the tire over the bar and into cutter blades mounted on a rotary blade assembly. The rotary blade assembly has a shaft mounted for rotation about an axis to the frame and has a plurality of cutter blades spaced about the shaft periphery. Each rotary cutter blade has a saw-toothed profile with triangular teeth. The tips or the moving blades are slightly spaced from the cutting edge formed on the fixed cutter bar.