How can you apply different thicknesses to individual faces while using the Shell command?

Applying different thicknesses to individual faces while using the Shell command is achieved by specifying an Alternate Thickness during the operation. When you utilize the Shell feature in Siemens NX, it allows for not just a uniform thickness across all surfaces but also an option to set specific thicknesses for different faces by inputting these values.

This flexibility enhances design capabilities, enabling the creation of complex geometries that may require varying structural properties based on the design intent. Using an Alternate Thickness is particularly useful in scenarios where certain areas of a model may need to be reinforced due to functional requirements or aesthetic considerations.

The other choices do not align with the correct method to achieve varying thicknesses. For example, simply double-clicking a face does not inherently allow for changing thicknesses; it typically accesses properties or constraints without the specific option for varying thicknesses. Stating that there is only one thickness in a shell contradicts the fundamental functionality of the Shell command. Lastly, while switching the shell type to variable relates to overall thickness flexibility, it is not the direct method for applying different thicknesses to individual faces, making it less correct in this context.