(1) The annealing of wrought iron gear required by this section must be accomplished at a temperature between 1100° and 1200°F. and the exposure must be of between thirty and sixty minutes duration. After being annealed, the gear must be allowed to cool slowly and must then be carefully inspected. All annealing must be carried out in a closed furnace.

(2) When heat treatment of loose gear made of other than wrought iron or steel is recommended by the manufacturer, it must be carried out in accordance with the specifications of the manufacturer.