This paper considers the conceptual value of social capital, given its contested empirical and theoretical purchase. It addresses how the use of the metaphor of capital to represent sociable and normative aspects of everyday life affects our sociological imaginations. The rhetorical force of metaphor inheres in its creative capacity to transform understanding and bring about enriched apprehension of the social world. Moreover, in social science writing it is considered invaluable to processes of knowledge transfer and engagement with different audiences, thereby enhancing the impact of social research. Yet its capacity to inspire the imagination underpins both its usefulness and its limitations. Using an empirical example, this paper illustrates how metaphor can curtail as well as enrich understanding in research. I begin by examining how metaphor ‘works’ in acts of communication, in general, before addressing – secondly – how social capital is applied analytically to the specific empirical field of ethnic social ties. This example illustrates how certain avenues of enquiry are effectively ‘closed down’ by accentuating the salience of social ties to the relative neglect of the political opportunities, institutions and resources within which they are situated. The third part of the paper considers what the metaphor of social capital achieves and precludes in our sociological imaginations.