This genuine part is a MTD hex nylon lock nut. It has a variety of applications in log splitters, riding lawn mowers, and lawn tractors. It is also known as a hex insert lock nut. A hex nut is used with anchor shackles, bolts, screws, and other externally threaded components. Used in conjunction with these other fasteners, the hex nut helps connect components to prevent tension and movement.A hex nut that has become worn, damaged, or lost can cause unsafe or unreliable operation of the unit. Hex nuts can be susceptible to thread galling or seizing, which can cause it to function improperly. Prior to working with this part, please refer to the original product manual for a full list of included parts and installation instructions. Additional tools may be needed for installation of this part. For safety, always wear gloves and ensure unit is powered down prior to performing any installation or repair.This high quality OEM replacement part is sourced directly from the manufacturer, and it is sold individually. It is made of high-quality durable metal. This part is compatible with Craftsman, Cub cadet, and more log splitters, riding mowers, and lawn tractors. Please note: original part number 712-3058 is now obsolete, and manufacturer has replaced the original part number with this part.