Base Flange/Tab

A base flange is the first feature in a new sheet metal part.

When you add a base flange feature to a SOLIDWORKS part, the part is marked as a sheet metal part. Bends are added wherever appropriate, and sheet metal specific features are added to the FeatureManager design tree.

The base flange feature is created from a sketch. The sketch can be any of the following contours:

Single Open	Single open contours can be used for extrudes, revolves, sections, paths, guides, and sheet metal. Typical open contours are sketched with lines or other sketch entities. Splines are invalid sketch entities for sheet metal parts with open contours.
Single Closed	Single closed contours can be used for extrudes, revolves, sections, paths, guides, and sheet metal. Typical closed contours are sketched with circles, squares, closed splines, and other closed geometric shapes.
Multiple Contained Closed	Multiple contained closed contours can be used for extrudes, revolves, and sheet metal. If there is more than one contour, one contour must contain the rest. Using the Contour Select in the PropertyManager, you can select one or more contours to convert into features. Typical multiple contained closed contours are sketched with circles, rectangles, and other closed geometric shapes. Multiple contained closed contours can also be disjointed. Typical multiple disjoint closed contours are sketched with circles, rectangles, and other closed geometric shapes.

The thickness and bend radius of the base flange feature become the default values for the other sheet metal features.