A meat grinder or meat mincer is a machine for grinding or fine mincing of raw or cooked meat, fish, vegetables or similar food. The operative puts the product into a tray, which is placed on the top of the grinder. From there the material goes on a horizontal screw conveyor. This screw conveyor, that can be powered by a hand wheel or an electric motor, squashes and partially mixes the food. At the end of the screw worm there is a knife installed directly in front of the fixed hole plate. At this opening the minced meat comes out of the machine. The fineness of the meat depends on the size of the holes of the plate.