... prevent local overheating caused by jagged and brittle fracture, Can also be caused by lack of penetration to prevent ... , serrated blade, the blade can’t be welded by resistance welding 5, less electricity ModelInput powerInput voltageOscillation frequency(Host ... , knives, saw bit, saw teeth, steel pipe, copper pipes, braze welding. SmeltingGold, silver, copper, aluminous and other metal smelting,. ...