In article .com,
says...
Anyone know where I can buy a 2 foot length of SAE threaded srteel
tubing?



Sounds like the connecting rods used between spherical rod ends.
McMaster only carries up to 3/4-16. Perhaps check with some of the rod
end manufacturers; Heim, Aurora, Morse, etc., or a bearing distributor.

Googling

"rod end" "connecting rod"

or

"spherical rod end" "connecting rod"

turns up some promising links.

Ned Simmons