OnePlus and Samsung have already received the newest Android's July security update, but now Android made the software available for Nexus devices. 

After update, the build version will change: 

 MTC19X for the Nexus 6P

MTC19Z for the 5X,

MMB30K or MOB30O for the Nexus 6,

MOB30P or MMB30M for the Nexus 7 (2013),

 MOB30P for the Nexus 5, Nexus 9, and Nexus Player.

As usual, it may take some time before the software hits your device. The manual installation is also possible.