... chipping, crackle, abrasion, wear and tear, miscalculation in manufacture repair metal tools/ better than Spot welder, Arc welder / cold ... defect in manufacture, welding defect.3. Suitable material can repair:Aluminum material, aluminum alloy, copper material, copper alloy, ... , and all electrical conductor.4. The position can repair: Sharp corner, sharp-edged orifice plate, groove or furrow, side wall ...