Mercury - Quicksilver 8M0204653 Prop Lock Nut Propeller & Drivetrain Hardware Stainless Steel 8M0204653. Overview. There's a certain confidence that settles in when you know your prop is locked down tight the kind of confidence that lets you open the throttle without a second thought. Out on the water, small details like a properly secured propeller make all the difference in how your boat feels and performs. This Mercury Marine part brings back that trust. It's the kind of hardware you rarely n