Example of Keep Body Option

When using the Convert to Sheet Metal tool, you can keep the solid body to use with multiple Convert to Sheet Metal features.

If Keep Body is not selected, the solid body will be consumed by the tool.

Machine with a sheet metal enclosure.
Use Convert to Sheet Metal to create the first sheet metal body. Keep body is selected. You want to keep the solid body to derive another sheet metal body from the same solid body.
Use Convert to Sheet Metal to create the second sheet metal body. Keep body is cleared so the solid body is consumed.
Until the solid body is consumed or deleted, it will be included in Mass Properties.