Section 1919.36 - Heat treatment(a) The annealing of wrought iron gear required by this part shall be accomplished at a temperature between 1100° and 1200 °F. and the exposure shall be of between 30 and 60 minutes duration. After being annealed, the gear shall be allowed to cool slowly and shall then be carefully inspected. All annealing shall be carried out in a closed furnace.(b) When heat treatment of loose gear made of other than wrought iron or steel is recommended by the manufacturer, it shall be carried out in accordance with the specifications of the manufacturer.