This screw is a genuine Midwest Engine replacement part for appliances operated by small engines, including lawn tractors, lawn mowers, snowblowers, leaf blowers, vacuums, and tillers. The purpose of a screw is to link materials together by piercing into the materials and then rotating it until the materials are firmly clasped together.It is likely that a screw will have to be replaced at some point in the lifespan of an appliance due to simply losing or misplacing the screw. If the materials that are generally supposed to be held together seem to be loosening or have come apart, it is likely that the screw has either fallen out or has undergone damage that has warped it. This kind of damage can be attributed to general overuse, to age, or simply to long-term exposure. If a screw is subject to any of this kind of damage, it is best to replace it immediately. Remember to always wear gloves when handling, repairing, and operating outdoor equipment. This screw is compatible with the following brands: MTD, Cub Cadet, Troy-Bilt, and Yard Machines. This part sold individually.