What is this tool for

[AGCB97]

What kind of machine uses it. Does it have any value to a hobbyist?

 

[T Bredehoft]

I suspect none of my machines would have the power to make chips with that. P & W is Pratt and Whitney, I expect this is a thread mill, but cannot imagine its use.

 

[09kevin]

Looks like it could be a serration cutter.

 

[Bob Korves]

Whitworth thread mill. My guess and I am sticking with it...

 

[682bear]

That is a B.F.T.

A big freakin' tap... lol!

It might make a good doorstop...

-Bear

 

[projectnut]

It's a gear hobb:
http://www.star-su.com/cutting-tools/gear-cutting-tools/hobs/involute

They come in many different sizes. They fit on a gear hobbing machine to cut various types of gears. Here's a video of some extremely large gear hobbing machines in action:

The one you have more likely fits a machine of this size:http://www.ebay.com/itm/BARBER-COLM...228190?hash=item43d29bb35e:g:bXEAAOSwuMFUZkxA

 

[Groundhog]

It's fer makin big stuff.

 

[Billh50]

Yep, that's a hob for making gears on a hobbing machine.

 

[Mark_f]

Yes, it is a gear hob. unless you have a hobbing machine, it is only good for a paper weight or doorstop.

 

[darkzero]

That would make one heck of a back scratcher.