Blank tie rod adjusting sleeves
I bought a bunch of aluminum, hexagon tie rod blanks from Speedway Motors, on clearance on Ebay, a few years ago. I think they were made by AFCO. They were gold anodized. Ended up getting the taps on ebay and bought a handful of lock nuts from Speedway as well.
EDIT In hind sight, they weren't blanks but they are very long and I can cut them down and retap them to whatever size I like. Looks like they have some 5/8" versions left on their garage sale section, but all of the 1/2" and 11/16" are gone.
Good luck!