In this work, we are interested in the multiphysics modelling of an arc welding torch. From the meshing viewpoint, we face the following difficulties: • welding tools can have complex geometric shapes, as can the parts to be joined; • maximum size constraints have to be satisfied on certain parts of the mesh, particularly at the interfaces. For example, the surfaces of the electrodes host a cathodic and anodic layer model of a given thickness and, more generally, thin boundary layers can be found in the physical solution; • the multiphysics model involves many physical unknowns. In order to ensure a reasonable computation time, it is important to control the number of mesh elements. Therefore, we rely on a topological anisotropic meshing algorithm first devised by Coupez and coworkers, which we have implemented in our in-house finite element software toolbox, Cast3M. Our contribution deals with the following aspects: • automate the computation of a suitable metric in order to drive the meshing algorithm; • optimize some parameters of the meshing algorithm itself (metric interpolation, boundary modifications, element quality criterion) in order to enhance the overall robustness of the mesh generation and the quality of the resulting mesh; • assess the suitability of the mesh for a typical multiphysics arc welding simulation.