I'll have to dig into it, but I suspect the good people at Alcoa buy raw billets of aluminum and then do the fine metallurgy themselves, whether making ducting sheets, metal for cans, or more exacting alloys and hardness ratings. So it's really unclear how tariffs would be applied, and by how much, to predict an impact.
Not to deny that I have more than a couple sheets of "mystery metal" in my airplane where it's not structural, mind you. The aviation section at Lowe's sells sheets of aluminum and steel by gauge and a rough stab at quality only.
As to HD, they're doing exactly what foreign car manufacturers learned a long time ago - the surest way to avoid a tariff is to build it in the country one would normally import to. Here in Alabama we have just about every automobile company, foreign and domestic, running factories.
