Solar Manufacturing received a vacuum furnace order from the U.S. Mint in Philadelphia, Pa. The furnace is Solar’s Model HFL-2624-2EQ and is essentially a duplicate of one provided to the U.S. Mint in Denver, Colo., in 2008. Both these furnaces are specifically designed to heat treat coining dies of material grades from A9 to CPM3V. The work zone is 18 inches wide x 14 inches high x 24 inches in diameter. The furnace will process work loads up to 750 pounds with a maximum operating temperature of 2400°F, and it will meet temperature uniformity requirements of specification AMS 2750D.
The furnace will pump to an ultimate vacuum of 10-2Torr with a leak-up rate of less than 5x10-3Torr per hour. The high-efficiency hot zone consists of four layers of ½-inch-thick, high-purity graphite felt with a .040-inch-thick Flex Shield hot face. Gas quenching is provided with an external 30-hp blower and a high-efficiency, all-copper, fin-and-tube heat exchanger operating at 2 Bar. This is accomplished with a full-locking autoclave door for the vacuum chamber.