It's still nothing more than a negotiating tactic. Canada and Mexico will be exempt on the NAFTA rework and the others need to bring something to the table.
He's not really looking for 25 and 10, but if he starts there and looks pretty hard ass about it, he'll get a lot more than if he went into this hat in hand.
And the thing is the target countries for the tariff is Europe notably Germany and China, the two biggest buyers of USA's value-added goods which is worth BILLIONS more, don't even need USA's goods; they all have a strong manufacturing themselves and are more than happy to produce and consume their own goods and not buy USA's crap. You think Germany with all their own Mercedes-Benz and Volkswagon really need and want to buy USA's Ford?
USA (the Republicans like the stupid George Bush Jr. mostly) has imposed tariffs before on steel imports and every single time when USA did that, it lost massive no. of jobs and economy suffered. I thought Trump would be different from Bush Jr. because he's a businessman, so disappointed that he's not. Anyway be prepared to buy lots of Puts.