Whatzit for #2 for today:

[Outlawmws]

This is a craftsman 1/2" drive square drive. probably modified but I guess it could be for something Craftsman sold..

The far side (ignore the aluminum clip that was simply to hold it for the pic) has a ball detent on the right end. the pin appears to be tool steel at least, and yes that is a set screw holding it in. the dia. of the pin would clearance a .312 hole, and is about 1.3 inches long.

Any guesses?

 

[lbgradwell]

Somebody made a device where he could use his drill to drive sockets...

 

[Jbullfrog]

That is one of the original power socket bits.

 

[chard98]

I have seen one before, Can't remember what the old guy said it was used for!

 

[Outlawmws]

I was cruising through one of the Craftsman Catalogs, and a thought occurred to me: could this guy be a part off of an impact wrench?