How do I desighn this?

[JimStaley]

I magine 3 concentric circles. Say, 6", 7" and 10" diameter. I want to carve the region between the 7 and 10" circles to 0.25" deep and the circlular region inside the 6" circle also to 0.25" deep.

[bjbethke]

I magine 3 concentric circles. Say, 6", 7" and 10" diameter. I want to carve the region between the 7 and 10" circles to 0.25" deep and the circlular region inside the 6" circle also to 0.25" deep.

Is this what you are looking for? You need to use the merge functions-also set your 7 inch circle to zero depth.