1.1 ,This test method covers the determination of the extrudability of unvulcanized SBR and NBR rubber compounds through a screw-type extruder equipped with ASTM Extrusion Die, Garvey type. This test method is designed to allow the observation of the appearance and contours of the extrusion. Rating systems are provided along with recipes for compounds of known extrusion characteristics. The utility of the test method for evaluating rubbers or compounding materials other than those listed has not been established. Since extrusion machines differ among laboratories, the procedure includes techniques that minimize differences between machines.