Use the Corner Round command to add fillets or rounds to one or more corners of a sheet metal part. All fillets and rounds created in a single operation are one feature.
On the ribbon, click Sheet Metal tabModify panelCorner Round.
Enter the radius for the first edge set.
Under Select Mode, choose Corner or Feature.
In the graphics window, select model edges that represent corners.
To add rounds with a different radius, select another set of edges.