My suspicion is that this wrench has been abused in the past
and then had the jaws ground or filed freehand in an attempt
to fix it. Look at the curve at the start of the fixed jaw
and the sharp 90 degree corner of the movable jaw. If it had
been manufactured that way, it would never have closed
completely.

I have a ten inch long or there abouts monkey wrench that I
have used a three or four foot pipe on that looks very
similar except for the fact that yours could never have
closed tight.

Also, this may have been manufactured as part of a line that
is mostly hand made where each movable jaw is fitted to the
individual wrench that it was sold with. If a person had two
of them, it would be easy to assemble them with mismatched
parts.

Ron


Bob Engelhardt wrote:
The jaws on this wrench are not parallel:

http://home.comcast.net/~bobengelhardt/wrench.jpg

Specifically, the face of the movable jaw is perpendicular to the
"ways", but the fixed face is not. But they aren't sprung or worn that
way. It seems that it was made like that. But why? Just plain poor
quality? But that's *really* bad. It's an old wrench, not Chiwandian.
It says drop forged, if that helps.

Bob