Defines requirements for resistance spot welding in the fabrication of assemblies of uncoated and metallic coated low carbon steel, comprising two or three sheets of metal, where the maximum single sheet thickness of components to be welded is within the range 0,4 mm to 3 mm, for the following materials: - uncoated steels; - hot-dip zinc or iron-zinc alloy (galvannealed) coated steel; - electrolytic zinc, zinc-iron, or zinc-nickel coated steel; - aluminium coated steel; - zinc-aluminium coated steel.