Radial metallicity gradient from open clusters studied in the framework of the Gaia-ESO (Baratella et al. 2020; Magrini et al. 2021, red circles) and APOGEE (Donor et al. 2020, green circles) surveys. Other similar clusters analysed by Alonso-Santiago et al. (2017; 2018; 2019; 2020, blue circles,) are also added, together with those previously investigated in the SPA project (Frasca et al. 2019; D’Orazi et al. 2020; Casali et al. 2020; Zhang et al. 2021, orange circles). Black lines link results for the same cluster provided by different authors. The star represents Stock 2.