Quattro Engineering India Ltd supplies Sheet Metal Machines. Quattro Engineering India Ltd supplies Machine Tools. The Sheet Metal Machines uses a series of rolls to form complex seams and flanges on lighter gauge sheet metal. The majority of roll-forming machines are geared toward fabricating duct and duct connectors for the HVAC industry. The Sheet Metal Machines uses a series of rolls to form complex seams and flanges on lighter gauge sheet metal. The majority of roll-forming machines are geared toward fabricating duct and duct connectors for the HVAC industry.