iPhone 8 to have stainless steel frame for its glass sandwich design

It's long been rumored that the iPhone 8 coming this year will not have a metal unibody construction anymore, instead opting to sport a glass back like Samsung's recent flagships. It's also been pretty well established that the phone will have a metal frame in between the glass on the front and that on the rear, thus employing the so-called 'glass sandwich' design. What hasn't been known so far is what exact material Apple chose for that frame. Now though courtesy of "sources from the upstream supply chain" we know it to be stainless steel. This will mark a big departure for Apple in terms...