A while back I had a fairly large slug of clay (about 6 pounds as I recall) centered on my wheel. Everything seemed normal. But as I started pulling up and thinning the walls of the pot, I noticed a wobble beginning to develop. As I continued to work the wall of the pot thin enough, I came to realized that the lump that was causing the wobble wasn't an irregular hard chunk of clay (a fairly common occurrence) -- no, it was a pan head machine screw.
I don't know how that screw got into the clay. My pug mill (a machine that I have that processes my clay) has a screen that is of fine enough mesh that I can't see how that machine screw passed through it. Anyway, I threw the screw into the nearest trash can, finished throwing that pot (wobble corrected), and completed a day's throwing of several more.
I closed up shop for the night, went in and ate dinner, had a beer, and watched an IU basketball game. Then, just as I was getting ready for bed, it struck me that something just wasn't right. I pulled my pants back on and dragged myself back out to the shop and fished the machine screw out of the trash can (no small sacrifice, as I had to dodge a paper towel used for an unpleasant clean-up that had occurred earlier that day --- a hairball incident involving our shop cat "the Diddiot").
Once I fished out the machine screw, I searched through my old coffee cans full of used nuts and bolts until I finally found a nut that threaded neatly onto the machine screw's threads. Then I threw the machine screw (secured with its nut) away.
Nobody wants to die with their calling unfulfilled.