any idea what this is?

[Pontiac Freak]

I found this in a box of tools I got from a gentleman that was selling all his items.

 

[Richard King]

That's one side of a Trammel for scribing lines on sheet metal or lay out on a any type of metal Like a compass with 2 metal points. I have one that doesn't have the fine adjustment There is a rectangular bar that slides into the slot and the top thumbscrew tightens down on it . I'm looking for one in a catalog so I can add a picture.
http://www.starrett.com/metrology/p...ools/Calipers,-Dividers-and-Tram/Trammels/50A

 

[Bill Gruby]

Starrett 50A Trammel. That is part of a two piece set. Sorry Richard, didn't see your link. I have a set that's how I knew what it was.

"Billy G"

 

[george wilson]

You can use a wooden beam like a yard stick to put the trammels on to make large circles.

 

[Pontiac Freak]

Thanks guys! I think I might have the other piece somewhere. Didnt realize what it was either.