We make a fair few of these style aluminium windows.  Commercial frame (101mm x 44.5mm) with an awning sash and lockable whitco chain winder.  Fly screen on inside.

The awning has no hinges or stays, and instead has a hook on the head and a matching hook on the top of the sash.  No moving on this turning point means nothing will wear out and break (as do hinges and non-friction stays after years of use)

Thought id take a photo before delivering it to a job site this morning.