An experimental investigation of the mechanical behaviour of three-sheet multi-material spot welded assembly is performed. An experimental device based on the Arcan principle is developed to test the three-sheet spot welded specimen under pure opening mode, pure shear mode and mixed opening/shear mode with three nugget sizes. A significant effect of the loading angle is reported and explained by three identified failure modes as a pull-out failure mode (pure opening), an inter-facial failure mode (pure shear) and a mixed pull-out/inter-facial failure mode (mixed opening/shear). A pronounced effect of nugget diameter size is reported on the ultimate force and the dissipated energy. A preliminary study of the strain-rate sensitivity of the three-sheet multi-material spot welded assembly is also undertaken.