Paragon heat treating furnaces, proudly made in America, have earned a fine reputation among some of the most discerning craftsmen in the world. The drop door counter-balance handle keeps the door closed tightly. The door swivels on a heavy steel rod with bearings. Paragon uses the reliable Orton digital temperature controller. Orton is well known for accuracy in the pottery field. Paragon furnaces include a door safety switch that turns off the heating elements when you open the door, yet the temperature controller remains powered. The furnace manual includes instructions for heat treating D-2, 440C, ATS 34, 154 CM, O-1, and A-2 high carbon steels.