Regarding Mass & Mast Breaking Strength in Oscar Fröberg's Calculation Tools

Can someone explain this to me, or point me to the documents here that relate to this subject?

How much 'Breaking Strength' do I need for X amount of sail? (Guessing there's more to it than that)

I contacted Oscar who graciously returned my email and told me something about the tool but he didn't remember the details. I guess he's been out of the loop for some time due to his job. He mentioned that breaking strength depends on thickness vs diameter, and

"...To get your needed mast breaking strength for your boat and proposed sail area Arne Kverneland has devised a simplified formula that bases it off the beam of your boat. Maybe you can find it on his knowledge page."

I'm in the US near Chicago and I think I have access to aluminum tapered poles (flag and light) of various diameters and wall thicknesses. I think this is more likely for me than building a wooden mast. Assuming that they will sell one to me. I contacted a manufacture of a fiberglass flag pole just to ask a preliminary question and when I told him what I wanted to do with it he ran for the hills! Hasen't returned an email since! :-)