An auger for a grinder material for a tire filling machine, having: a cylindrical column; and a plurality of flights extending outwardly from the cylindrical core, wherein (i) the flights are arranged in pairs extending radially outwards from the cylindrical column at 180 degrees to one another, and (ii) each flight has a sharpened leading edge. Each pair of flights are positioned at angles of approximately 50 or 60 degrees to one another, and each flight extends approximately half way around the circumference of the cylindrical column, and there are no outer edge notches in the flights.