Ducts come in various lengths depending on the fabrication equipment available to the contractor. We have a Auto Duct Making Coil Line where sheet metal comes from the manufacturer in large coils of various gages (Thickness).
Typical sheet metal coil widths is 48 inch (1220 mm).  So 1220 mm is usually the standard length of the sheet metal duct that we can fabricate and supply. We can also flat sheets of 4 ft x 8 ft and fabricate ducts that will have a duct length of 8 ft.
Automated Coil Line ensures fast production of Ducts and dimensional accuracy and quality.
Ducts can be shipped fully assembled or in knocked down “L” sections. Having the duct shipped in “L” sections (knocked down) allows for more sheet metal to be shipped as it is easy to nest them together.
Generally, five types of duct joints are made by us.
1. S & C (S Cleat and C Cleat)
2. TDF
3. Sheet Flange
4. Slip-on-flange
5. Angle frame flange
Using CNC Plasma Cutting Machine and Rollformer etc., we also make all types of Rectangular Duct Fittings. Images of some standard types like 90 degrees elbow, 45 degree elbow, Double elbow or Y piece, Square to Round etc are shown below.