Valve?

[Badknuckles]

Is this a valve? If so what for?

[leg17]

looks like an arbor for some sort of cutting tool.

[amecks]

How about a pop-up sprinkler head?
Al

[thiggy]

I vote for some type of nozzle.

[Badknuckles]

Well my first thot also was sprinkler head but it doesn't pop open. It's a 3/4 X 16 thread. Notice the little Alan head retaining screws. If it gets twisted 90º the head would come off. There is no passage thru it for something to flow thru. The little holes in the head are thru holes from those retaining screws.  It needs a 1-1/8 wrench on the nut and shaft so it must have been for some hefty purpose. If that is so what's with the tiny retaining screws?  Whole thing weighs about 2 lbs.

My conclusions are:
It has to turn 90º to actuate
It has to handle some humongous force when in use
When not in use the forces are minimal.

Brilliant Huh?

[amecks]

Another guess.  A centering tool for a brake lathe?  It has two tapers.  The larger taper is removable so it has two sizes.
Al

[Davetoombs]

I'm on board with a 'centering tool' but not familiar with brake lathes. To be sure I understand, this is a self aligning 'dead center'. The 'collar' is removeable so that a collar with a different diameter or bevel angle can be used? On track?

Dave

[oldgoaly]

I've got a old Bear drum lathe I use now and then, nothing like that with it?
If it looks like a nozzle could it be from a chemical sprayer like farmer use? there were lots of them made.

[Badknuckles]

Based on your suggestions of a centering device I polished up the end cap and the pointed support. It looks to me like vertical marks on the end cap suggestive of centering. The support rod looks like it has supported multiple end caps of various sizes.

Wadaya think?

[amecks]

Possibly for a regular machinist lathe.  There are "dead" centers and "live" centers.  Live centers spin via bearings.  Dead centers don't spin.  They are just clamped in place.
An image search shows a few similar shapes but no exact match.
Al

[Badknuckles]

The head can be easily removed by rotating it 90º  and looks to me like another head, presumably with a different angle, can be easily substituted. The circumferential grooves in the supporting conical end suggest great force applied when in use. The wrench size (1-1/8") also implies great force.

The entire thing is steel except the head which is non-magnetic and might be beryllium-copper (just a guess). The vertical marks on the head suggest to me great force applied and if it actually is Be-CU that would make sense as that is tough stuff.

I think the whole thing is slipped into a holder of some sort then run up against something that needs to be centered but for what reason I cannot imagine.

Wow! did I write all that?