Mill Volume is not a single feature. It is a set of features that are referenced by a milling NC sequence. All chunks of volume are machined by generating a continuous tool path, but each chunk of Mill Volume is considered as a separate feature. For example, if you gather references, add a sketched volume, and offset walls, three features are added to the workpiece.

You can delete or suppress mill Volumes, or their portions by deleting or suppressing the appropriate features on the workpiece. Select the volume chunks by selecting them on the screen (use Query Sel if necessary), or by feature number.

You can also modify the dimensions of a volume (such as sketch dimensions, offsets, round radii) by right-clicking the feature in the Model Tree and clicking Edit from the shortcut menu. You can then select the volume features as you would select regular part features. You can modify the dimensions of a volume only if the volume is unblanked.