If you have an awning window hinge stamped 30122 and 31701, they you probably have the Truth Awning Hinge 13.13.  Although this is a awning hinge, we sometimes find this hinge on casement windows as well.  As with any number we find on Truth Hardware, these stamping numbers lead us to the conclusion that you have the 13.13 hinge.  The numbers we find stamped on Truth parts are just stamping numbers, but when we find both numbers, you can be 99% certain that is what you have.  On this hinge the track length is 10″ long.   The arm going from the lower right corner up a 45 degrees would be screwed into the side of your window.  The black shoe is steel coated in acetate (plastic).  The most common problem we see with this window hinge is the black slide wearing down and pulling out of the track.  This causes the window to pull out of the track and come crashing out.  We stock this hinge and sell them in pairs (one left and one right).  Our part # is Wi1313, and they can be ordered on our website.

The above hinge is stamped 30122 and 31701. You may find other numbers, but these are the most common found on this hinge.