I drive a subaru with all season tires which have around 7/32" of tread left in the center of the tire, and the tires had 10/32" when new. I thought I had a puncture that couldn't be repaired, but when I took the screw out tonight, it ended up being a pretty small screw. The tire is off the car, but still holds air just fine with the screw removed, I don't think it came close to fully penetrating the tire. So what do you guys think, could the little screw have done any real damage?