Size #56 meat grinder plate Rare. 1/4 (6 mm) holes for larger hamburger grind Stainless Steel commercial size meat grinder plates. Fit Hobart, Biro, Berkel and other heavy-duty size #56 meat grinders. This is the plate with the 1/4″ (6 mm) holes for burger size ground meat Plate is 6″ (152 mm) diameter. 13/16 (20.8mm) center hole. North America’s largest selection of stainless steel. Meat grinder parts and accessories.