OTC Daihen India Pvt. Ltd. Construction & Architecture Products - December 5, 2019December 5, 2019 OTC Daihen India Pvt. Ltd. These welding processes are very efficient however limited on a usage. Metal Arc Welding (GMAW) is relatively flexible in the usage but multi-layer welding is required for heavy plate since rated output of GMAW is limited up to 500A in general.