Don't mean to pick at your suggestion but wouldn't it equate to 1.5mm wall thickness? Anyway the stuff you buy from the likes of Goodall, etc.. is 'drawn' aluminium which is a bit stronger than the normal hardware store aluminium. I think the Goodall type tube must be around 1.2mm wall thickness and hardware shop stuff 1.5mm. So I suppose they'd fairly equal at the end of the day, although the hardware stuff is heavier.