A knuckle pin, coupling system, and method for producing a knuckle pin are provided, the knuckle pin having a cylindrical body with a longitudinal slot therein separating vertical edges of the cylindrical body, with one or more first retaining elements that span outward of the cylindrical body, and a second retainer that includes one or more of opposing apertures, and bendable legs. A method for producing the knuckle pin is provided, where a blank is stamped into a workpiece that corresponds to the pin to be produced, and the stamped workpiece is rolled to produce the pin with the slot.