Spherically averaged radial profile of the mass-weighted (solid lines) and L_X-weighted (dotted lines) iron mass fraction of the hot CGM of gimic galaxies, binned by M₂₀₀ as in Fig. 5. The profiles of haloes of all masses exhibit a negative gradient. Mildly supersolar abundances are exhibited at the halo centre; the mass-weighted profiles drop to a few per cent of solar at the virial radius, whilst the L_X-weighted profiles tend to a tenth of solar, highlighting the presence of a bias in the metallicity measure at large radii. The inset panel shows mean mass-weighted iron mass fraction obtained by integrating over all hot CGM gas within a radius r. See the text for a discussion of these biases.