TDC FLANGE FROM CHINA MANUFACTURER TDF (Transverse Duct Flange) system: The flange is formed from the same sheet as of the duct. TDF Duct Corner: -- Thickness: 0.8 mm ~1.2 mm (18~23 Gauge) TDC (Transverse Duct Connector) system: A separate flange install onto the ductwork TDC Duct Corner: -- Size: 20 mm / 25mm/30 mm/35mm / 40 mm -- Thickness: 2.0mm / 2.5mm / 3.0mm / 3.5mm
