No. The blade, called a mixing knife, in a Thermomix® is engineered in a way that prevents the blades from breaking. The shaft of the mixing knife is equipped with a safety breakpoint outside the bowl, so the pressure required to break the knife will break the shaft before the blade. The blades in a TM5/TM6 do not have rivets nor any pieces that could break free. The blades have undergone rigorous testing in many scenarios to be safe.