The soak band consists of the through-thickness volume of metal, which is heated to the minimum but does not exceed the maximum required temperature. As a minimum, it should consist of the weld metal, HAZ, and a portion of the base metal adjacent to the weld being heated.

The heated band consists of the surface area over which the heat source is applied to achieve the required temperature in the soak band and limit induced stresses in the vicinity of the weld. It should consist of the soak band plus any adjacent base metal necessary to both control the temperature and limit induced stress within the soak band.