Today's Monument

Many times pto and axle shafts were smaller in diameter than the splines to reduce the amount of steel and/or increase the capacity of the lubricant case.

Here's a 1000 rpm PTO shaft.

Note how the splines extend much farther than the shaft you found. Also, there is the groove where the locking pin locks the drive shaft onto the power shaft.

Here is a John Shaft

Note the badass attitude and cool seventies facial hair. Also, this cat won't cop out when there's danger all about. Can you dig it?

Thanks Cow. I suppose I am thinking of a much older type of pto shaft. I was thinking of something like this:

http://www.ebay.com/itm/E5NNA728AA-Ford-New-Holland-Tractor-PTO-Shaft-2600V-2610-2810-2910-3000-/231099551083

.. or maybe this type ???

http://www.agkits.com/ford-pto-shaft-htd8nn7a684ba.aspx#.WWdIrzOZNGM

Around here, that's an IPF. Unless you set it, then it's an IPS.

That's a "Leaning Shaft" better contact McMillan. 😉

Interesting. That would be inside the tractor. Not familiar with those. The one in my photo is the standard final shaft, exiting the tractor for connection to powered implements via the pto driveline(s).