Screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter-pins, washers (including spring washers) and similar articles, of iron or steel.
7318.21
-- Spring washers and other lock washers
Section XV
BASE METALS AND ARTICLES OF BASE METAL
Chapter 73
Articles of iron or steel
Heading 7318
Screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter-pins, washers (including spring washers) and similar articles, of iron or steel.