What is the size difference, in size, between size A (gudebrod) nylon thread and a 3/0 tying thread?

I know gudebrod size A is .006 diameter and 2.7 lb break strength.

I bought some size D gudebrod nylon (rod winding) thread for some 1/0 bass flies. I think it is about twice the diameter of size A. The 6/0 black thread I had was just too small. I am going to give the size D a try as they did not have size A in black.

Thanks.