Unsplit Surface Edges
Use the Unsplit tool to remove split lines so that split surfaces return to their previous unsplit state.
Note: This tool is supported for FE geometry.
        - 
                From the Topology ribbon, click the arrow next to the
                        Split tool, then select
                        Unsplit.
                

Figure 1. - 
                Select points, lines, or surfaces.
                
- Unsplit will suppress fixed points.
 - Free and shared surface edges are handled differently. For free edges,
                            the below options are available:
- Generate a straight line between vertices
 - 
                                            

Figure 2. - Extending the edges using adjacent edges as a guide
 - 
                                            

Figure 3. 
 - Select surfaces to remove all split lines for one or more surfaces
 
 - Click Unsplit on the guide bar.