The corner edit dialog box lets you can specify an overlap type overlap gap relief type and relief size that differ from your sheet metal style or from the default value specified in the active sheet metal style.
Inventor sheet metal corner seam.
To specify an overlap that differs from the value specified select overlap type in the corner edit dialog box.
To specify an overlap gap select overlap gap.
You can create a corner seam or rip an existing corner seam between sheet metal faces.
The default settings for the sheet metal rule define the default values for the options.
To create a three bend corner you can use corner seam or auto miter.
Click the corner edit glyph for your selected corner.
About sheet metal parts.
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.
Create corner seam between sheet metal faces create seams between faces that intersect or are coplanar.
On the ribbon click sheet metal tab modify panel corner seam.