I have found that Caterpillar bolts are very strong and also machine like butter! I scrounge them from mechanics and truck shops, but the black oxide coated ones are cheap enough from Cat to buy new when I don't have one in stock that will work.
I make studs, special bolts, pins, and shafts from them all the time.
For a stud like this application, I would use a NF bolt and cut the coarse threads a little large on the lathe. I have a fixture for drilling the cross-hole that is sold by aircraft supply houses.