This industry comprises establishments primarily engaged in the merchant wholesale distribution of supplies for machinery and equipment generally used in manufacturing, oil well, and warehousing activities. Illustrative Examples: Industrial containers merchant wholesalers Industrial diamonds merchant wholesalers Printing inks merchant wholesalers Industrial sand merchant wholesalers Refractory materials (e.g., brick, blocks, shapes) merchant wholesalers Welding supplies (except welding gases) merchant wholesalers Cross-References. Establishments primarily engaged in--