Salt bath furnaces operate by heating and maintaining a bath of molten salt at the desired process temperature. The workpiece is directly immersed in the molten salt, which provides extremely rapid and uniform heat transfer due to the high heat capacity and thermal conductivity of the liquid medium. Heating is accomplished through external resistance heating, internal immersion heaters, or electrode heating (where electric current passes through the salt itself). The buoyancy of the salt supports the workpiece, reducing distortion. Temperature uniformity within the bath is typically ±2°C, far superior to atmospheric furnaces. Different salt compositions are used for different temperature ranges: nitrate salts for 150-550°C, neutral chloride salts for 700-950°C, and barium chloride salts for 950-1300°C.