A professional who controls furnace to harden, anneal, or temper watch parts. Respnsibilities include:

• Presses button to admit gas mixture, forcing air out of furnace and burning mixture at entrance to prevent discoloration of parts and to maintain carbon content in parts.
• Places parts in metal basket or cylinder and inserts parts into furnace according to specified temperature.
• Advises on furnace temperatures and heat-treating time periods, and recommends procedures to produce desired hardness.
• Quenches pieces with air or oil.
• May cover parts with charcoal to prevent rapid heating causing discoloration of parts.
• May insert thermocouple into furnace and connect thermocouple to recorder.