Abstract: The invention is concerned with an improved grinder useful for grinding meat, which grinder includes a first section for coarsely grinding the meat followed by a second section for more finely grinding the meat, the two sections including screws which are coaxial with each other and driven by a common power source. The improvement comprises a cylindrical section intermediate the coarse grinding section and the fine section, the intermediate section including a shaft coaxial with both of the screws and connecting one screw to the other with a chamber surrounding said shaft. The shaft includes two partial screw threads both of which have pitches greater than the pitches of the threads in the two grinding sections.