<p>Aluminium alloy components are increasingly utilised in the automotive industry due to their lightweight properties, contributing to improved fuel efficiency and reduced emissions. Many of these components require specific surface roughness profiles, which can be achieved through milling operations. However, excess material from upstream processes, such as residual flash from the demoulding process, presents challenges for the machining process. These irregularities, combined with stringent demands for specific roughness, burr-free edges, and flatness, require careful selection of tool microgeometry, tool grade, and cutting parameters. Nonetheless, research concerning the behaviour of polycrystalline diamond (PCD) tools when machining aluminium alloys remains limited, and existing studies often fail to address the complexities of high-volume production. This study, therefore, examines the performance of PCD tools in the high-speed milling of aluminium components. A total of 60,000 components were machined over an eight-month analysis to compare tool life across different PCD grades and tool microgeometries. The research reveals that medium-grained PCD tools lead to superior surface quality and a 22% longer tool life. Tools with larger nose radii (0.09 mm versus 0.06 mm) demonstrated significantly higher performance, reducing burr formation by 15% while maintaining lower surface roughness values. Insert height positioning emerged as a critical factor, since reducing deviations between insert heights substantially extended tool life and ensured consistent surface roughness. The findings provide practical criteria for selecting PCD tools and their microgeometry, directly impacting cost efficiency in high-volume automotive component manufacturing.</p>