Here is what I was told by someone that is doing the same thing I am doing which is using this pipe for carport/shop legs(mine may actually turn into a shop)I'm wanting to use this to build a covered patio... so curious as well
the legs will be in the ground so you want the thicker pipe so it doesn't rust through
i'm either gonna try to use thick(.220) walled 2 3/8" pipe or I may go to the 2 7/8" and see what wall thickness it has.(i think my truss legs will accomodate the larger pipe but I will need to measure.
OR, I may end up using the thinner walled structural 2 3/8"(3/16" wall) pipe