Our Duct TDC flange machine was specially designed to manufacture the Slip flange, widely adopted in HVAC Ducting system. The TDC flange can customized designed according to client requirements from 15mm to 50mm, suitable for medium and large producers of square HVAC duct. If you are interesting our flange making machine, pls contact with us freely! Jv@jack-aiva.com / whatsapp +86 13915206868