Just looks to me like a stud. Sometimes called a "bull" stud. Large end
could be for repairing stripped out stud hole or just for increased thread
strength in aluminum or other soft material.
Don Young

"Christopher Tidy" wrote in message
...
Hi all,

Today I found something weird inside the vice of my power hacksaw. I've
noticed a rubber boot inside the vice before, which I thought protected
the screw thread from chips. But today a bit of the rubber cracked off,
and it didn't look much like rubber. It looked more like that peelable
plastic that is used to cover cutting tools, so I became curious and
pulled this item out from the vice:

http://www.mythic-beasts.com/~cdt22/weird_object.jpg

It was resting on top of the vice screw behind the fixed jaw, so it didn't
affect the operation of the vice. The question is, what is it? To me it
looks like a fluteless thread forming tap, but it's double ended and the
threaded sections aren't tapered, so I'm puzzled. It's 5 1/2" long, 1 1/8"
diameter at the small end and 1 1/2" diameter at the large end. Both screw
threads are right handed and it says "T22 HF" on the large end.

Any idea what it is?

Chris