You can insert a tooling split to create the core and cavity blocks for a mold. To create a tooling split, the part must have at least three surface bodies in the Surface Bodies folder: a core surface body, a cavity surface body, and a parting surface body. You can create a mold from a tooling split for multiple parts, or for multiple instances of the same part.
To help prevent the core and cavity blocks from shifting, you can add an interlock surface along the perimeter of parting surfaces prior to inserting a tooling split in a mold part. You can also create the interlock surface automatically when you insert the tooling split. To close holes in a molded part, you can add shut off surfaces.
If you do not include the surface bodies with the mold part in advance, you can include a collection of separate surfaces that the tooling split command can automatically knit together.