Quick Guess Time: Will 1/2" Wide Be Enough?

The hexagonal tube mounting rings will consist of two layers of 1/8" thick 6061 aluminum.  I can either make them 1" wide or 1/2" wide.  From experiments with making these 1/2" wide, my guess is that two rings that are effectively 1/4" thick and 1/2" wide are probably sufficient to hold a 60 pound tube without flexing.  Two such rings would weigh 1.60 pounds; if they were 1" wide instead, they would weigh 3.20 pounds.  Obviously, reducing weight is still a critical issue for me.

I am going to have my local metal retailer cut these, but once I have bent them, there's no easy way for me to cut 1" wide down to 1/2" wide.  Any guesses as to whether 1/2" wide will be stiff enough?