On the ribbon click sheet metal tab modify panel corner seam.
Inventor sheet metal corner seam.
To specify an overlap that differs from the value specified select overlap type in the corner edit dialog box.
Specify any of the following in the corner edit dialog box.
Create corner seam between sheet metal faces create seams between faces that intersect or are coplanar.
About sheet metal parts.
To create a three bend corner you can use corner seam or auto miter.
To specify an overlap gap select overlap gap.
Click the corner edit glyph for your selected corner.
An automatic corner feature occurs when you create two flange features using identical parameters on adjacent edges of a sheet metal face.
You can create a corner seam or rip an existing corner seam between sheet metal faces.
To create a three bend corner you can use corner seam or auto miter.
You can change the values for an individual corner.