enveloped by the vacuum, the hot metal flows from the VIM furnace crucible into giant electrode molds. A typical electrode is about 15 feet (5 m) tall and will be in various diameters. The electrodes solidify under vacuum. For VIM-VAR steels, the surface of the cooled electrodes must be ground to remove surface irregularities and impurities before the next vacuum remelt. Then the ground electrode is placed in a VAR furnace. In a VAR furnace, the steel gradually melts drop-by-drop in the vacuum-sealed chamber. Vacuum arc remelting further removes lingering inclusions to provide superior steel cleanliness and remove gases like oxygen, nitrogen and hydrogen. Controlling the rate at which these droplets form and solidify ensures a consistency of chemistry and microstructure throughout the entire VIM-VAR ingot, making the steel more resistant to fracture or fatigue. This refinement process is essential to meet the performance characteristics of parts like a helicopter rotor shaft, a flap actuator on a military jet, or a bearing in a jet engine. For some commercial or military applications, steel alloys may go through only one vacuum remelt, namely the VAR. For example, steels for solid rocket cases, landing gears, or torsion bars for fighting vehicles typically involve one vacuum remelt. Vacuum arc remelting is also used in production of titanium and other metals which are reactive or in which high purity is required. See also Flodin process Vacuum arc remelting References Further reading J.A.T. Jones, B. Bowman, P.A. Lefrank, "Electric Furnace Steelmaking", in The Making, Shaping and Treating of Steel, R.J. Fruehan, Editor. 1998, The AISE Steel Foundation: Pittsburgh. p. 525–660. Thomas Commerford Martin and Stephen Leidy Coles, The Story of Electricity, New York 1919, no ISBN, Chapter 13 "The Electric Furnace", available on the Internet Archive External links Recognition of first foundry as historical site Home made small scale arc furnace using a welder (Caution with experiments!) Electric Arc Furnace module at steeluniversity.org, including a fully interactive simulation Process models demonstrate the EAF operation and control (MPC) YouTube video of a small EAF in New Zealand Electric arcs Industrial furnaces Steelmaking