In this study, we examine transformations in the influence of risk experts in two large UK banks over a period of six years. Our analysis highlights that a process we term toolmaking (whereby experts create tools that embody their expertise) is central to the way in which experts garner influence in complex organizational settings. We develop a framework that conceptualizes the transformations in the influence of experts via two interdependent processes. First, experts can change their knowledge from personally communicable, tacit knowledge into tool-generated, highly communicable knowledge. The second interdependent movement involves how experts develop their personal involvement in producing analysis and interpretation in important organizational decision-making forums. Based on the ability to combine and balance these two processes, we distinguish analytically among four positions of influence that experts can occupy-box-tickers, disconnected technicians, ad hoc advisors, and frame-makers-and trace the movements of experts between these positions. The findings and theoretical framework contribute to our understanding of how and why experts can become influential, complementing existing explanations focused on (a) the cognitive and political dimensions of what influence-seeking organizational actors do and (b) the structural conditions under which they operate.