Ninja blades are standard stainless steel with exclusive sharpness. To retain sharpness of the ninja blades even years after is purely dependent on the handling strategy by the consumers. He or she should follow the do’s and don’t s with the Ninja blenders and its blades, specially. Experts who assembled the food processor recommend six factors that blunt the blades of your kitchen appliances. Ice cubes, dried fruits, mashed tubers, hot soupy liquids, utensils and dough are addressed as not recommended ingredients incorporate into Ninja blenders of any model. Desperately either of the case would damage the blades of your Ninja professional model. Recalling of few models of Ninja product line might be due the certain reasons that blunt the blades. Crush the ice cubes before blending, stop using spoons until the blender fully blend your ingredients. Similarly, let your hot liquid ingredient few minutes before introducing it into the pitcher. Close the lid promptly while the blender functioning. Avoid sudden blasting of ice cubes unless your Blender empowered high wattage.