I'm looking for an Andersen storm window corner from what I see it's about 5/16 wide and a 16 in thick I sent a picture
Dave Sr. from SWISCO responded:
May 4, 2022
We don't have a corner key that matches your dimensions, unfortunately, However take a look at 95-004 or 95-054 . I cannot guarantee that these will work, but if you're handy then you may be able to adapt one to work in your frame.