273 Style Rocker Arm Adjusting Screw

I dont recall rethreading the screws, but the threads will "change" somewhat going thru a grade 8 nut.
Thanks I ground flats on mine a while back. What I would really like to know is when you have two threaded parts are both set up with interference threads like what I have? This doesn’t seem correct as they are way too tight when both engagements close. I would think either the nut would have the interference thread or the stud but not both like I have.