Material flow analysis (MFA) has been an effective tool to identify the scale of physical activity, the allocation of materials across economic sectors for different purposes, and to identify inefficiencies in production systems or in urban contexts. However, MFA relies on ignoring the social drivers of those flows to be able to perform its calculations. In many cases therefore, it remains detached from the processes (e.g., urban) that underpin them. This becomes a problem when the purpose of research is to inform the design of detailed recycling schemes, for which micro-level practice knowledge on how material flows are mediated by human agency is needed. The aim of this article is to demonstrate how a particular social science approach, namely, infrastructure studies (IS), can be combined with MFA to enhance the latter's potential as a decision support tool. To achieve a successful combination between IS and MFA, the object of inquiry must be carefully defined to function as a ‘boundary object,' which allows academic approaches to work together without the need for consensus. This approach is illustrated with a case study example in urban mining research that assesses the hibernating stock of subsurface urban infrastructure in Norrköping, Sweden. It provides an example of how a well-calibrated MFA and a complementary social science approach can provide hands-on advice for private as well as public actors in a local and place-specific context. The article aims to advance the integration of social science and the study of the physical economy to contribute to the emerging field of social industrial ecology.