I have a 1/2" diameter hole. I want to put a pipe inside the hole. What size PVC pipe fits into a 1/2" hole?

Did you guess 1/2" pipe? WRONG. "1/2 inch pipe" isn't half an inch big on the outside. It's closer to 7/8". You might think "ah so the 1/2" refers to the inner diameter". Wrong. The inner diameter of 1/2" PVC pipe is legally required to be 0.602 inches, according to the Schedule 40 standard. Want a pipe with outer diameter 1/2"? The closest size of PVC pipe is of course 1/4" PVC pipe. But even that won't quite work, because, 1/4" pipe has outer diameter 0.54", which is more than 0.5" and way more than the 0.25" in the name of the pipe. PIPE SIZES ARE ALL LIES

Guess how I found out? I'm building a telescope, and as part of that I'm building a mount. I bought a cheap collection of 3 pipes off the internet, but I needed a fourth, so I went to the hardware store to buy some pipe. Guess who learned a $6.99 lesson in nonsensical standards...

i added some interesting looking games other people found in this to my list, so if you bought any bundle, please check it out. there's some overlap so you might have some of these.