US Patent 7909337 Gasket

A gasket which can uniformize the facial pressure on the thickened part more securely is to be provided. A gasket comprises a pair of base plates and stacked above and underneath, in which combustion chamber holes and bolt holes are bored, a doubling plate and shim plates intervene between these base plates. On this doubling plate, a second bead, which permits plastic deformation, extends in the circumferential direction of each combustion chamber hole. As the second bead is deformed according to the magnitude of the fastening load, the gasket height lowers where the fastening load is heavy and the facial pressure on the peripheries of combustion chamber holes is uniformized after fastening.