They are produced in the U.S. in more than modest quantities. We exported 7.6 million metric tons in the first three quarters of last year, mainly to Mexico and Canada. The two countries who export to us and who we are going to hit with a 25% tariff. We import virtually no steel at all from China.
We also exported almost three million tons of aluminum.
"Bridge Comes to San Francisco With a Made-in-China Label"
http://www.nytimes.com/2011/06/26/business/global/26bridge.html
So, if we’re exporting Steel and Aluminum to Mexico and Canada then why are we importing, from who and are they dumping it?
Why does it matter if we slap tariffs on them when we and exporter nation?