Section 15 Base metals and articles of base metal 73 Articles of iron or steel 73 18 Screws, bolts, nuts, coach-screws, screw books... of iron or steel 73 18 19 Threaded articles, nes, of iron or steel Commodity Code Description 73 18 19 00 Threaded articles, nes, of iron or steel 73 18 19 10 Having a shank of an external diameter not exceeding 16 mm 73 18 19 90 Other