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 Refractory materials (e.g., brick, blocks, shapes) merchant wholesalers Industrial diamonds merchant wholesalers Welding supplies (except welding gases) merchant wholesalers Printing inks merchant wholesalers Cross-References. Establishments primarily engaged in--