Guess that bolt ....new game

Try and guess what part the bolt is for based on the caption given which is a clue along with the specs. of each bolt.


Caption: I live with five of my buddies for a total of six of us. we have large shoulders as seen in the pic which makes us fairly unique.

the is a lot of PRESSURE on our shoulders ....but together we do an important job keeping it together and share the pressure equally amongst us