I sometimes volunteer at a local detention facility, and they have a metal
detector. Last night I was up there and hadn't had time to change out of my work
clothes, and I triggered the metal detector even with no metal on my person
whatsover. The guy running the wand asked me if I happened to work in a machine
shop and I said yes, and he said work jeans from a machine shop or steel fab
shop can trigger a scanner no problem.

I would have never guessed. Turned out this particular officer used to be a
machinist, and he had specific knowledge on the subject.

I'll be danged.

GWE