The notion status of word-combinations “social engineering” and “social machine” is considered in the paper in the context of comparison of “physics” and metaphysics of a social. Making a reference to the use of the word-combination “social machine” in the works by N.Winner on the one hand, and to accusation of mechanicism on the other hand, the author analyzes the transition from the metaphor to the notion of “social machine”. The distinguishing of social and engineering proceeded on the basis of overcoming the empirical and transcendental subjects which took place after Kant, in theoretical sociology in particular. Such notions as “engineering collective” (F.Yunger) and the notion “mega-machine” or “big social machine” (L.Mamford) are worthy of attention within the framework of philosophy of engineering. On the grounds of comprehension of modern social realities, in the theory of management in particular, the author suggests to introduce the notion “small social machine”, concerning small “engineering collectives”. The consideration of a social machine as a method of mediating and a component of social relations should favor in general the extension of the horizons of social vision.