Sub-contract heat-treatment specialist Keighley Laboratories of West Yorkshire (U.K.) enlarged the size of one of its largest pit furnaces, increasing dimensions to 1,110 mm (43.7 inches) working diameter and almost 1,800 mm (71 inches) maximum length, gaining 30% in overall capacity. Enlarging the No 1 pit furnace involved fabricating a custom-made inner shell, or retort, made from exotic duplex stainless steel. The investment has already been offset by orders for heat treating 1,108-mm-diameter (43.6-inch-diameter) gear wheels for an offshore application and 1,755-mm-long (70-inch-long), 1-metric-ton shafts for a renewable energy project. The furnace project has opened up a new market for Keighley Laboratories amongst engineering companies and OEMs looking to heat treat larger components. The company employs its pit furnaces for carburizing, carbonitriding, hardening, tempering and stress relieving, working at temperatures up to 980°C (1796°F).