You might be able to make a replacement, by getting a long bolt in that thread size (preferrably high-strength stainless, or at least grade 5 plated), cut to length, and lock a couple nuts on it, torqued against each other hard, and you just use one of those nuts to adjust the joint, as there is zero tension or resistance on it when the joint is open.

Yes , I thought that will be my only solution , I have researched quite a bit , couldn't find the exact part . Thanks !