This article argues that the politics of socio-material objects should be examined in relationship with the machineries of knowing these objects are embedded in and also sustain. Objects of expertise are embedded in discursive constructs, material infrastructures, and relationships that “surround” and permeate their production. In turn, such objects give traction to the machineries of knowing that enable their emergence. The article uses the concept of “knowledge machinery,” coined by sociologist of science Karin Knorr-Cetina, to denote a focus on the “machinery” and its “parts” at the same time, or to the “macro” and the “micro,” as highly intertwined and mutually reinforcing in processes of knowledge production. The article explores these questions in the context of global health governance, with a specific focus on the politics of mobile health and the data it generates, conceived as an object of expertise of its own kind. It shows, first, that mobile health data have specific characteristics and claims attached to them; they are, in themselves, the turning of bodies and lifestyles into standardized and fully mobile “data units” that feed into data flows. As such, they produce ordering, norming, and governance effects, which do not disrupt but sustain the knowledge machinery of global health.