Green hydrogen is gaining moment across Europe as feedstock, fuel or energy carrier and storage, as solid actions are needed to reach carbon neutrality by 2050. Hydrogen has many possible applications across industry, transport, energy and building sectors and, therefore, local gas grids across Europe are working hard to get ready for its transport. The realization of the prospects of delivering H2/NG admixtures or even 100 % H2 by existing gas distribution grids exacerbates the problem of pipe integrity due to the well-known negative impact of hydrogen on the mechanical properties of metals. Most projects assessing safe hydrogen compatibility with natural gas distribution grids (i.e. H21, HydePloy,etc.) have performed experiments to study the leakage ratio, emission potential and explosion severity of vintage components. However, long-term material integrity assessment replicating distribution grid operating conditions in testing platforms is still necessary. CANDHy will allow the possibility of testing relevant metallic materials, different from the well-studied steels, with a methodology involving simultaneous test in independent R&D platforms with a common methodology. This will allow to obtain trustful and reproducible results about hydrogen tolerance of materials that have not been considered in previous research but that are an essential part in in low-pressure gas grids. CANDHy project will enable hydrogen distribution in low pressure gas grids by consolidated and exhaustive scientific data, coupled with harmonized guidelines for non-steel metallic grid materials. At least five material grades of different families (such as cast iron, copper, brass, lead, aluminium), both new and vintage, will be fully documented, and the results will be publicly available for all stakeholders in a continuously updated database. Mechanical tests will base on static and dynamic conditions to assess hydrogen sensitivity following the most relevant current and updated standards