It's 3 3/4" long - 1 5/8" dia. - & 2"dia. and weighs 2 lbs 4 oz.
Not sure of it's original purpose, but looks like you could balance a lawn mower blade with it.
Probably a center for a lathe?
Really big dowel centering pegs? For transferring hole centers?
(https://s.yimg.com/lo/api/res/1.2/De0PWetPJS4Cy4E_qcwRLQ--/YXBwaWQ9eWlzZWFyY2g7Zmk9Zml0O2dlPTAwNjYwMDtncz0wMEEzMDA7aD0yNTA7dz00NTA-/http://toolmonger.com/wp-content/uploads/2008/02/Dowel%20Centers.jpg.cf.jpg)
center for a lathe
Hard to tell from the third photo down but it looks like unpointed end has a hole in it. If so, it could be a plumb bob — home made? The pointed end would need to screw or otherwise come off in order to insert a stash of string. And at 2 lbs. 4 ozs., it'd hold still in a pretty good gale, I reckon.
In the 2nd picture the shaft looks tapered, is that correct? I'd toss my vote in with the lathe center group.
Chilly