Section 15 Base metals and articles of base metal 73 Articles of iron or steel 73 22 Radiators for central heating, not electrically heated, and parts thereof, of iron or steel; air heaters and hot-air distributors (including distributors which can also distribute fresh or conditioned air), not electrically heated, incorporating a motor-driven fan or blower, and parts thereof, of iron or steel Commodity Code Description 73 22 11 - - Of cast iron 73 22 19 - - Other 73 22 90 - Other