The Century Line knives have been especially designed for intense use. They receive a thermal treatment which consists of hardening (heating the blade), subzero (cooling from 50 to -196 degrees), and tempering (increasing the steel elasticity) for a longer and more efficient life. Made of polycarbonate and fiberglass, the handle is directly injected on the steel bolster and finalized with aluminum rivets. The Century Line has a 25-year warranty covering manufacturing faults and is certified by the NSF, National Sanitation Foundation, an organization internationally recognized by its consultancy, inspection, and training practices aimed at guaranteeing the sanitation of food, water, air, and the environment.