I forgetfully wore steel toes boots through a WTMD in PHX a few years ago, pre-shoe removal days, and kept alarming the WTMD. I had emptied my pockets and looked at the screener in disbelief. He pointed down at my shoes and I realized my mistake.

I felt pretty dumb about that one.

You'll have to take them or any other shoes off anywhere in the US so it won't be a problem.