This is a hex head bolt 1/4 - 28 x .625. It is used to secure a device together for smooth and simple operations. With use and over time, the hex head bolt may be damaged or come loose and fall out. When the bolt is missing, the machine could fall apart or otherwise malfunction. Be sure to replace a missing or damaged hex head bolt.Allow the equipment to cool completely before starting the repair process. An Allen key or hex key will be required to loosen and remove any old or damaged bolts. The new bolt can then be inserted and secured tightly. Examine for other missing parts before starting the device.The hex head bolt 1/4 - 28 x .625 is an authentic OEM part. It is sold as an individual unit. It is made of rugged, durable, high-quality materials. The hex head bolt can be used in lawn equipment machines, including various models of tillers. It is compatible with MTD, Yard Machines, Yard-Man, Troy-Bilt, and Cub Cadet brands.