Section 15 Base metals and articles of base metal 73 Articles of iron or steel 73 02 Railway or tramway track construction material of iron or steel, the following: rails, check-rails and rack rails, switch blades, crossing frogs, point rods and other crossing pieces, sleepers (cross-ties), fish-plates, chairs, chair wedges, sole plates ( Commodity Code Description 73 02 10 Rails 73 02 30 Switch blades, crossing frogs, point rods and other crossing pieces 73 02 40 Fish-plates and sole-plates 73 02 90 Other