A method of manufacturing a jaw member of an end-effector assembly includes forming one or more stress-relief cavities within a sealing plate. Each one of the one or more stress-relief cavities defines a pad portion of an electrically-conductive surface of the sealing plate. The method also includes forming a stop member on each pad portion of the electrically-conductive surface of the sealing plate, performing an overmolding operation wherein the one or more stress-relief cavities is configured to prevent force applied to a bottom surface of the sealing plate during the overmolding operation from stressing each pad portion to avoid compromising adhesion between the stop member and the electrically-conductive surface of the sealing plate.

An apparatus is provided for a powerplant. This apparatus includes a pilot chamber structure formed as a monolithic body. The pilot chamber structure includes an exterior surface, an interior surface, a pilot chamber, a pilot aperture, a fuel aperture and an ignitor aperture. A material property of the monolithic body may change as the pilot chamber structure extends between the exterior surface and the interior surface. The interior surface forms an outer peripheral boundary of the pilot chamber. The pilot chamber is internal to the pilot chamber structure. The pilot aperture projects into the pilot chamber structure to the pilot chamber. The fuel aperture projects into the pilot chamber structure to the pilot chamber. The ignitor aperture projects into the pilot chamber structure to the pilot chamber.

An apparatus is provided for a powerplant. This apparatus includes a pilot chamber structure formed as a monolithic body. The pilot chamber structure includes an exterior surface, an interior surface, a pilot chamber, a pilot aperture, a fuel aperture and an ignitor aperture. A material property of the monolithic body may change as the pilot chamber structure extends between the exterior surface and the interior surface. The interior surface forms an outer peripheral boundary of the pilot chamber. The pilot chamber is internal to the pilot chamber structure. The pilot aperture projects into the pilot chamber structure to the pilot chamber. The fuel aperture projects into the pilot chamber structure to the pilot chamber. The ignitor aperture projects into the pilot chamber structure to the pilot chamber.