Round edges

Fillet a solid’s edges with a radius.

Round adds a fillet to a solid’s edges, softening them by a radius you control. It rounds the outer edges by default; set Edges to Inner to round the inside corners instead — smoothing out the joints where one part meets another — or Both for every edge. It is a parametric modifier you can re-tune or remove.

1. Select a single solid.
2. Open Modify → Round edges.
3. The Properties panel opens on it — set the radius in Edge size.