provided differ from the members in the first embodiment the load acting portions are provided on both outermost externally toothed plates 6 in the axial direction of the clutch portion a protrusion 14 is formed on a surface opposed to the urging surface 7 a of the piston 7 of the externally toothed plate 6 adjacent to the piston 7 the protrusion 14 is formed as a semi spherical configuration extending in the axial direction accordingly when the piston 7 applies the urging force to the clutch portion a curved surface of the protrusion 14 abuts against the urging surface 7 a of the piston 7 on the other hand a protrusion 15 is formed on a surface opposed to the backing plate 3 of the externally toothed plate 6 adjacent to the backing plate 3 the protrusion 15 is formed as a semi spherical configuration extending in the axial direction accordingly when the piston 7 applies the urging force to the clutch portion a curved surface of the protrusion 15 abuts against the surface 3 a of the backing plate 3 also in this embodiment so as to satisfy the relationships described with reference to fig1 the protrusions 14 and 15 are formed so that they are positioned on a substantially the same single straight line parallel with the central axis of the clutch portion the protrusion is formed integrally with externally toothed plate adjacent to the backing plate and the protrusion 14 is formed integrally with the externally toothed plate adjacent to the piston 7 fig3 is an axial partial sectional view of a wet type multi plate friction engaging apparatus.