I’ve always wondered about this too, but I inclined to think they are 7075 the hardest alu aloy. I mean it holds our lives up there, we want medium strength of the 6061 or exceptional strength of the 7075?
But I’m curious about the answer…
I would not look at the files properties for reference that was just to get the weight of the bars. The bars are 7075-t6. There is not a list of the materials but the frame is 6061-t6.