slotting - pricking wheel?

[PFSchaffner]

Another curiosity from the current batch of donations to the Ann Arbor Kiwanis thrift sale.
Made of iron. Small: the two wheels (which turn together on the same axle when cranked)
are a little more than inch in diameter. Presumably fits into or onto something else, but I
do not know what, or even what sort of material it works on, or what effect it is intended
to have.

[turnnut]

it looks like it could be a ring cutter to resize,  used by a jeweler.

   ( a finger ring)

[wvtools]

Yes, it is a ring cutter/saw.  You can find them in the reprint of the Young's jeweler's/watchmaker's catalog circa 1899.

[PFSchaffner]

The MWTCA reprint? I have that one and didn't think to look there. I will. Thanks.

[PFSchaffner]

It's worth posting the entry from the Otto Young catalogue (as mentioned above), for the benefit of those who don't have a copy, since the resemblance between catalog picture and actual object is remarkably exact.

[Billman49]

Does the right hand wheel have file teeth on its face???

[PFSchaffner]

I would have thought it would, and I will look again tonight. But my recollection is that as it stands now, the right-hand disk is fairly smooth to the touch.

[turnnut]

if I remember right, you cut the ring with the blade and then smooth the two cut ends til they are the right
 fit,

to make a ring smaller.

[PFSchaffner]

The slotting wheel is thin steel, with teeth.
The jointing wheel (right) is thicker, and covered with fine parallel-cut lines, like those of an extra-fine file, on both surfaces.

This particular example has signs of damage: the platform through which the slotting blade protrudes is, I think, meant to be flat, but this one is bent at the saw slot, as if from being dropped. And the jointing wheel has apparently been broken in half and brazed (?) back together again. Also, I would guess, from being dropped.

[PFSchaffner]

Here is a closeup of the jointing wheel, showing the file-like striations, and also what I take to be
the accidental crack.