Having a brain fart....what the heck is the bolt and nut called that looks like two bolts that screw together? Insert nut? Needing a very low profile bolt/nut setup.
A sex bolt, (also known as a barrel nut, barrel bolt, 'Chicago screw' or post and screw), is a type of fastener (nut) which has a barrel-shaped flange and protruding boss that is internally threaded.