Nitrogen is liquid at below its boiling point of -196°C (-320.4″F). In the liquid state, 4.0 L (1.06 gallons) of nitrogen will produce 20 m3(706 ft3) of nitrogen gas at 21°C (70°F) and 101.4 Ha (14.7 psia). Liquid nitrogen is used extensively for metallurgical purposes. For example, metal parts such as pins, shafts and similar pieces are cooled in liquid nitrogen to effect shrink-fitting of assemblies. See CRYOGENICS.