No, you should never put stainless steel knives into a dishwashing machine, even if the included instructions say it is safe to do so. The high-pressure water jets can knock the knives into the racks or other utensils in the dishwasher, reducing the blade’s edge. The hot water and chemicals in the detergent can also stain the steel. Hand washing the knives and drying them immediately is the best way to preserve their integrity.