3535 Conveyors and Conveying Equipment Establishments primarily engaged in manufacturing conveyors and conveying equipment for installation in factories, warehouses, mines, and other industrial and commercial establishments. Establishments primarily engaged in manufacturing farm elevators and conveyors are classified in industry 3523; those manufacturing passenger or freight elevators, dumbwaiters, and moving stairways are classified in industry 3534; and those manufacturing overhead traveling cranes and monorail systems are classified in industry 3536.