Agricultural implements. 15th census of United States [1930]: Manufactures, 1929, industry series, agricultural implements; doors, shutters, and window sash and frames, metal; galvanizing and other coating, not done in plants operated in connection with rolling mills; iron and steel, processed; safes and vaults; steel barrels, kegs, and drums; structural and ornamental iron and steel work, not made in plants operated in connection with rolling mills; windmills and windmill towers.