In several instances chemical abundances of main-sequence and giant stars are used simultaneously under the assumption that they share the same abundance scale. It is therefore crucial to understand whether the metallicity or abundance differences among dwarfs and giants are real or are produced by systematic errors in the analysis. We aim to ascertain a methodology capable of producing a consistent metallicity scale for giants and dwarfs. To achieve that, we analyzed giants and dwarfs in the Hyades open cluster, under the assumption that they share the same chemical composition. All the stars in this cluster have archival high-resolution spectroscopic data obtained with HARPS and UVES. We analyzed the sample with two methods. The first method constrains the atmospheric parameters independently from spectroscopic method. We show that it is possible to obtain a consistent metallicity scale between dwarfs and giants. In our test, the metallicities derived with the well-constrained set of stellar parameters are consistent independent of the line list used.