Use the Sweep modifier to extrude a cross-section along an underlying spline or NURBS curve path.
You can work with a series of pre-made cross-sections such as angles, channels and wide flanges, and can also use your own splines or NURBS curves as custom sections.
This modifier is also very useful for creating structural steel details, molding details, or in any situation where you need to extrude a section along a spline. It is similar to the Loft compound object but is more efficient.
Note: The Sweep modifier is similar to the Extrude modifier in that once the Sweep is applied to a spline, the end result is a 3D mesh object. Both sections and paths can contain multiple splines or multiple NURBS curves.
Examples of extrusions created with the Sweep modifier