possible door hinge pin

[Bounder]

I dug this up in my own yard. We live in the house of an old farm that an old lady in her 90's said had its own blacksmith shop. This pic is after a wire brushing. It has no threads or hole in the end for a cotter pin. It also appears that the crown has been pressed on rather than machined.

 

[wolf-n-wa]

Looks like the locking pin for train car coupler. "Knuckle pin"

 

[hoser]

I've seen very large conveyor chain that used pins just like that.