How Do You Bend A Sheet Metal Flange?
Standard sheet metal flanges are used for mounting accessories to duct work. Sheet metal flanges can be bent to any size, but there are two common types of flanges. The flange is designated by the direction that the flange bends on the duct. A “flange in” is, as the name describes, turned to the inside of the duct work and a “flange out” bends to the outside of the duct work. Both flange types bend the same way; the difference is how you lay out the bends for the flange versus the layout marks for the duct work. Set the scribe to 1 inch. Run the scribe along the edge of the ductwork that is going to receive the flange. Measure across the sheet metal with the tape measure and use the permanent marker to lay out the locations of any bends that will need to be made across the duct’s sheet metal flange. Cut a straight line with the aviation snips at each bend location that you marked in Step 1. The cut needs to extend the full 1 inch width of the 1 inch flange. Notch the corners of the fla
