The window screen corners have been breaking. None of the local hardware stores stock anything in this size. The pieces are about 5/16 thick, but I didn't see anything like it on your website. I purchased the windows from the "Heritage Window" Co., in Mesa, AZ.
I dragged out my micrometer and measured the part. It measures 0.325" thick and 0.521" tall (as it is positioned in the photo).
