Commercial Grade replacement knife. This Listing is for the. Size replacement meat grinder knife. Fits many brands including Hobart, Biro and others. (Some Toledo Scale grinders). (Lifetime Guarantee against rust). Size #42 replacement knives Premium. Fits most #42 size Electric grinders with plates that are 5 1/16 across. 7/8 (22mm) center square hole. Will fit your grinder if your plates are 5 1/16 across. North America’s largest selection of stainless steel. Meat grinder parts and accessories.