Abstract: A unitary boundary gasket is adapted for sealing between flanged portions of two axially mated surfaces of rigid metallic members, such as between the bottom of an engine block and an associated engine oil pan. In one preferred form, the gasket has a rectilinearly shaped annular body, and is formed of a one-piece radially outermost rigid metallic carrier having a first axial thickness, and adhesively bonded to a one-piece radially innermost elastomeric sealing body. The sealing body is bonded to the metallic carrier at the radially innermost edge of the carrier. The sealing body includes a plurality of spaced elastomeric apertures adapted for accommodating passage of bolt members for fastening said flanged portions together about the gasket body. The apertures are designed for sealing against leakage of fluids between said apertures and said bolt members. For this purpose, each aperture includes at least two axially spaced integral sealing lips.