Here's how to make two different ring designs out of a brass nut!
Step 1: Materials
Metal files of assorted sizes
Sand paper (grit depends on the finish you want)
Drill and 5/8" bit
6v lantern battery
Step 2: Drill Out Threads
I don't have a picture of this but put the brass nut into the vise and drill out the threads.
Step 3: Grind Off All Corners But 2 (or 3 Depending on the Design)
Just do what the title says. The picture for this step is taken after I sanded the inside to size.
Step 4: Sand the Ring
Use your sandpaper to adjust it to your preferred size and finish. Use rough grit to shape it and gradually work through the finer grits to finish it.
Step 5: Design 1: 3 Etch Spots
Mix a good amount of salt with some water. Cover the entire ring with masking tape and cut out three circles on the faces and a small strip in the back of the ring to connect the wire to. Connect one wire to the positive of the battery and place it in the water. Connect the other wire to the negative and to the ring and place it in the water. Wait a few hours and there should be a small etch on the three spots. This isn't the best way to etch metal but it worked for me.
Step 6: Crown-ish Ring
If you do this design, use a round file to remove and round out the faces. Polish it and done! This one had a brushed finish.