In inventor thicken offset command use to add or removes thickness to faces of a part or a quilt. Create an offset surface from a part face or surface, or a new solid.
To select tangent continuous part faces, use the automatic face chain option. To add sides between the original surface and the offset surface, use the create vertical surface option.
Where do I find it?
3D model -> modify -> thicken/offset.
How to use inventor thicken offset command?