METHOD OF DETERMINING METAL GASKET WELDING LOCATION

A welding position is provided which can prevent surface pressure drop in a seal bead in a pair of metal gaskets is determined. Joint surfaces of a pair of metal gaskets are joined to each other by welding. The pair of metal gaskets include a seal bead that encloses opening and a plurality of structures that bulge from the joint surfaces. A pressure-sensitive medium is sandwiched between the seal bead and a member to be engaged so that the pair of joined metal gaskets and the member to be engaged are stacked on one another, and the pair of joined metal gaskets are tightly engaged with the member to be engaged. The tight engagement is released, and a surface-pressure-drop location in the seal bead is detected based on a mark which remains on the pressure-sensitive medium after the release of the tight engagement. An additional welding position is determined in a rectangular area which is defined by four sides contacting a first structure closest to the surface-pressure-drop location and a second structure closest to the first structure to surround the first structure and the second structure.