It also means less demand for such products. Users of infrastructure will face higher costs as well. Construction services are driven by real estate development and by creation of new infrastructure - every sort of project in power, roads, transportation, telecom, etc, requires construction. Net-net, that will mean less jobs for Americans. Job losses downstream will outnumber jobs protected in metals production.
In a more generic way, as inflation rises, consumption may ease down, leading to lower GDP growth. Meanwhile, jobs will also be lost in more competitive metals-producing countries, which can no longer export to the US. So, there will be a slowdown elsewhere as well. As the US-made goods become more expensive, America may decide to impose tariff barriers in downstream industries. Indeed, Trump has threatened import tariffs on European cars (and on Indian two-wheelers). And, of course, trade partners could retaliate.