In search of replacement pivot bars
It looks like you have two different styles of pivot bar. Could it be that the one on the left is just an updated version of the older one on the right? That would definitely make things a little easier. Can you also tell me the distance between the center of each screw hole to the front tip? That will help us find something that will fit in the same space.
Oh, weird. Not sure why they used two different kinds of pivot bars during installation, but I suppose stranger things have happened. I think your best bet is either our 26-226 or 26-342, depending on your hole placement. You'd only use one of these for both the top and bottom sash, assuming the hole placement is the same for both of your pivot bars.
As for why they broke, they usually snap if the window is tilted in before being raised a few inches first. That puts too much strain on that part of the window and either breaks the pivot bar or pivot shoe, or both. In the future, always make sure to raise your window up 3-4 inches before you tilt it in.
