Peening has been employed in the welding industry for some thirty-five years. It is a mechanical process administered manually by hammer blows or pneumatic tools. Peening a hot weld stretches the weld material, and, in doing so, helps compensate for the shrinkage that occurs during cooling. This is especially helpful in the welding of close tolerance molds and dies where even low amperage micro-tig welding can cause residual stress and dimensional distortion. Micro-peening even the smallest of welds can reduce stress, minimize distortion and can aid in the reduction of sink to help prevent cracking in the heat-affected zone