Wow this administration is f**ing batshit insane. I thought the tariffs would be on raw metals, not anything at all that happens to contain them.
First of all, if you want to use tariffs to boost domestic manufacturing, you must also tax the steel/al content of finished (or intermediate) goods. Otherwise, you put your local producers at a disadvantage, making the tariffs worse.
If you only tariff raw materials, then an american manufacturer has to pay either US steel prices or imported steel + tariff to manufacture, but a company overseas can use the cheaper foreign steel.
So if you want to tax raw materials, then you also want to tax those goods where raw materials are an important part of the cost.
The US has a catalog called the "Harmonized Tariff Schedule" (HTS) which is a catalog of basically everything under the sun [0]. When the steel & AL tariffs were announced, they also published a list of all the HTS codes where the steel/al content would also be taxed.
Last week the US published a revised list of HTS codes to which these tariffs apply, and they added about 400 items to them. For example, the aluminum content of cans is now taxed when it wasn't before.
Flexport has a very cool (and useful!) tariff simulator where you can look up any item and it will tell you if the steel/al content will be subject to these tariffs: https://tariffs.flexport.com
Don't some tariffs motivate people to do processing offshore?
If I import 1kg of copper and machine/etch/whatever it down into products, with some wastage, maybe I should just do everything offshore and only import the final articles with 500g of copper in it.
At some point, higher tariffs on input materials will overtake the higher value of finished goods and you might as well just manufacture the whole thing offshore anyway.