The means of forming the electrical contact between the two wires of a thermocouple. Methods include: Type E; soft or silver soldering for low temperature operation. Type J, K, T; Gas Welding; the wires are twisted together through two or three turns, held vertically in a vise and joined by fusion with a gas flame (usually only borax as a flux). Arc Welding: for small or medium diameter wires. Requires no flux. The arc is struck between the twisted tip and a piece of carbon rod. Resistance Welding; for all thermocouples of very small diameter wires. Uses a capacity discharge type welder. Useful for R, S, B, C, W, J, E, T & K. K Factor A number based on the harmonic content of load current that determines the maximum safe loading on a power source.