Abstract: A support for the carriage of a welding head intended for the automatic welding of metal plates comprising plane areas framed by corrugations running in two perpendicular directions and intersecting to form abutment surfaces at the ends of the corrugations. This support comprises a base equipped with means for fixing the base to one of the said plane areas, means for centering the base with respect to the corrugations surrounding the plane areas by contact with a plurality of the said abutment surfaces, and adjustable stops for defining the distance from the base to the plane area by contact with a plurality of the said corrugations, the said base including means for mounting on the base a guide bar designed to receive the said carriage translationally.