According to the rumors, Samsung is expected to use more glass in the Galaxy S7’s build and will feature a glass back panel. However instead of using an aluminum unibody, Samsung is rumored to use magnesium alloy which is supposed to offer up a stronger and more durable build.
Given that Apple has also turned to a stronger version of aluminum for the iPhone 6s and 6s Plus, we suppose this doesn’t really come as a surprise. As it stands, the Galaxy S6 is said to feature the grade 6013 aluminum, so presumably the Galaxy S7 will be a stronger build. Take it with a grain of salt for now, but last we heard the handset is rumored for a launch in January.
To be more specific, the rumors state the 19th of January which is after CES 2016. This means that we could be looking at an announcement prior to MWC 2016 if that is the case.