I used to work part time at a service station while I was in school. Had a guy roll in a flat tire that looked to have a piece of 1/8 - 3/16 dia steel sticking out of the tread. No matter what I used, I could not pull it out, so I broke the tire down off the rim. Inside the tire, at the other end of the steel rod I was trying to remove was the handle of a screwdriver. How that happened still baffles me.