Welcome to TNet Jimmy.
Here is the scoop, the world is covered with iron junk. All of us find assorted iron object all of the time. I call them all "tractor parts". Most people use the machine's discrimination to filter the iron signals out. Large rusty iron can make a high sound, that we associate with good targets.
I am certain that is what Perses meant. He just forgot that you are new, and that we were all new at one point, and brought home a tractor part or two. It's all good brother!
Best of luck to you sir!