Nail sizes are kind of odd. A 10d nail (10 penny) is 3 inches long, and is called a "10 penny" because, at one time, you paid a dime for 100 of them.. Similarly, a 16d nail would cost you 16 cents per hundred.
What does this have to do with bicycles? Very little, actually.
But, one day, on my way to work at Destinations, I ran over a 10 penny nail. I was riding my DiamondBack Avail cross bike, with 32c knobby tires and a sweet pair of Sun Rim/Shimano Deore DX 700c wheels. As I ran over the nail, the rear rim suddenly became a lot less sweet.
The nail somehow penetrated not only the tire, but it also pierced the rim, itself. I had never seen such a thing, and I was a little concerned about how I was going to get work.
I pulled the nail out, and removed the tire and tube. Luckily, I had a full patch kit with me, and I was able to use some patches to boot the tire and cover the hole in the rim. When I put the new tube in, and aired the tire up, I was just waiting for it to blow out of the hole in the rim. But, it held.
So, I rolled on in to the shop, and hung the bike up in my stand to try and patch the rim a little better. I planned on buying a new rim, but I needed to get home, that night.
"What the hell happened to your wheel?" Scott asked me.
"Cops shot my tire out, because I wouldn't stop when they tried to pull me over," I told him.
One of the mechanics looked up, wide-eyed, and said, "Really?" I think he actually believed me.
Hey, he was a bike mechanic...not a rocket scientist.