Nanotechnology is a unique field encompassing many disciplines and specializations. Collaboration between firms is important the development of the field and collaboration across sub-fields may be particularly beneficial – stimulating innovation through the exchange of information. Based on a survey conducted on 242 Massachusetts nanotechnology firms, I explore the underlying factors that encourage and direct collaboration between firms. Firms are often embedded in several different networks of association – with university collaborators, industry-wide associations, informal networks of information transfer, and field identity. I consider whether these loose associations lead to more tangible types of cooperation between firms, and explore what factors push firms to create diverse ties across disciplines. Finally I consider how the resulting structure may impact firms and the industry.