Median angular momenta in the r, ϕ, and z directions – 〈L_r〉, 〈L_ϕ〉, 〈L_z〉 – plotted against the median metallicity, 〈[Fe/H]〉. Each panel presents the angular momentum in a specific direction. Marker colours represent distinct HC groups, consistent with the other figures in this paper, while marker shapes indicate different stellar movements: inward churning, outward churning, and blurring (labelled as ‘equal’). The lines serve as visual guides rather than regressions, highlighting potential trends: the solid line connects HC groups with inward churning, the dashed line corresponds to outward churning, and the dotted line represents stars with unchanged radii (undisturbed or blurred).