Heretofore grommets have been either cemented within the walls of openings formed in cylinder head or manifold gasket bodies, as shown and described in McDowell U.S. Pat. No. 4,103,913, or have included flanges which are adapted to projecting into the gasket body material, so as to be anchored permanently therein adjacent an outer metal layer, as shown and described in Aukers U.S. Pat. No. 2,395,243. Other gasket bodies have been known to include means for mechanically clinching its grommets, such as by the use of dovetail-shaped slots formed at spaced intervals completely through the gasket body material around the periphery of each opening.