The Mold tools in SW are not useful to a large degree. Their biggest draw back is that they are not associative to the design model if a change is initiated by the customer. It is better to use tools like the "cavity" feature in an assembly environment. Then you can replace the part with a new one and just reselect the new one as the body to subtract in the cavity feature and it will update. If you use the Mold Tools in SW everything goes haywire if you try to replace the design part.