I just found this forum and it is awesome! This may be a bit of an oddball question, but does anybody have suggestions for materials that come in 2” OD sizes? Of course pipe is generally measured by a nominal diameter and then an ID, but tubing sometimes is measured by OD. I know exhaust tubing comes in 2” OD, but was wondering what else might be out there. Any thoughts on other materials that come in 2” true OD sizes?

It would be nice if you told us what it is your going to be using it for.
And yes it does make a differance.
Filling a door knob hole, filling a hole in a concrete wall, a hole in a hardwood floor, ECT. all would take differant materials,

plastic rod, ceramic rod, tubing... get online to McMasterCarr.com if it absolutely, positively has to be 2 inches, no matter what. unlike the box stores, their stuff is cataloged in thousandths of an inch.

otherwise, if you have a specific need for generally availiable and cheap stuff, pick up a dial caliper in aisle whatever, take it to aisle yasure, find what you need, and drop off the caliper or buy it on the way to the register as you need/want.

I likes me a dial caliper. a $30 indulgence that I've pulled out three or four times a year for 22 years now.