Establishments primarily engaged in performing the following types of services on metals, for the trade:
(1) enameling, lacquering, and varnishing metal products;
(2) hot dip galvanizing of mill sheets, plates and bars, castings, and formed products fabricated of iron and steel; hot dip coating such items with aluminum, lead, or zinc; retinning cans and utensils;
(3) engraving, chasing …
