Twister T4 Nitrided Bed KnifeReplacement Twister T4 Nitrided Bed Knife Note: * New FoodSafe Nitrided Blades ship standard with all Twister trimming machines (T2, T4, and T6). Nitrided blades are high carbon, hardened steel blades that surpass the quality and durability of most standard blades on trimmers. Nitrided Blades are FoodSafe; the materials used are approved for contact with food products. 600 hour lifespan depending on environment & operator Hardened steel Increased