Nrs unbendable is 6061-t6 1.25" schedule 40 pipe ~1.66OD pipe. Are you looking for telescoping tubing to join two pieces of their pipe?
Unbendable means you cant put it in a bender and get smooth curves due to the temper. If you whack it hard enough (read, big rock), it will bend
Hey, if you want me to take a dump in a box and mark it "guaranteed", I will. I got spare time.