Section 16 Machinery and mechanical appliances; electrical equipment; parts thereof; sound recorders and reproducers, television image and sound recorders and reproducers,and parts and accessories of such articles 84 Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof 84 57 Machining centres, unit construction machines, etc, for working metal 84 57 20 Unit construction machines (single station) Commodity Code Description 84 57 20 00 Unit construction machines (single station)