Pins located on sash broken

I've been replacing coil balaces and pivot shoes on various windows over the past few weeks and I've come across the pins broken on the bottom of the sash. I'm not familiar with the name of the items. But it appears that there is a threaded whole at the bottom that has seem to have snapped off. The screw is still in the side of the sash. Pictures are attached. Any help identifying these would be great. Thanks!!

Brian