The use of hot work tool steels is widespread in the production of tooling dedicated to metal forming processes, including forging and high-pressure die casting. A viable strategy to mitigate thermal gradients and enhance temperature distribution, thereby optimising the metal forming process and the working condition of the tool, is the production of tooling with internal hollow shapes and conformal cooling channels. The application of innovative metal additive manufacturing techniques, such as electron beam melting (EBM) offers a competitive advantage in the production of components with complex shapes that would otherwise be unattainable through subtractive manufacturing. However, due to the rapid melting and solidification process starting from a material in powder form, the materials produced by additive processes are often characterized by anisotropic microstructures, high residual stresses and microstructural inhomogeneity.