Selecting the filler metal should not be a trivial matter.  The easy way out is to select a filler metal that has matching strength, meaning that the minimum specified tensile strength of the filler metal matches that of the base metal. However, this is not always the best option. In some cases it may be beneficial to use undermatching filler metals.  There are many factors to consider when selecting the right filler metal. Understanding requirements in the areas of strength, ductility, wear resistance, corrosion resistance, in-service demands, cost and productivity is essential.