Best way to anchor aluminum tube

[liquidsords]

I have a 1" OD aluminum tube w/ approx. .08" wall x 12" long, and I would like to insert some sort of well nut or rivet nut at the top of the tube. The tube is counterbored to allow room for the head of the nut. I have no experience with these so I was wondering if anyone could help me out. It looks like rivet and well nuts are used for holes in thin metal so I don't know how it would anchor itself inside a tube. ANy suggestions?

 

[btrueblood]

Spotface (create a flat spot) the area on the o.d. of the tube where the rivet will engage.