... , crackle, abrasion, wear and tear, miscalculation in manufacture repair metal tools/ better than Spot welder, Arc welder / ... in manufacture, welding defect.3. Suitable material can repair:Aluminum material, aluminum alloy, copper material, copper alloy, low carbon steel ... cast iron, cast aluminum, tungsten carbide alloy, and all electrical conductor.4. The position can repair: Sharp corner, sharp ...