This is a genuine OEM replacement part designed for use with a variety of power tools. It is made out of metal and it is sold individually. It is a standard hardware which has multiple applications based on your tool. You would need a wrench to tighten/loosen this nut.
This is a genuine manufacturer sourced replacement part used on Delta and Black and Decker equipment. It helps to distribute the pressure evenly and provide a tight seal between connected components. This is a standard hardware which may have multiple applications. For the exact location please refer to the diagrams of your specific model. This part is made of high-quality metal and is sold individually.
This is a genuine Delta replacement part. The hex wrench is designed by the manufacturer for use in power tools such as planers, jointers, and drill presses. This part is made of metal, and is a replacement for a tool that came with the original machine. This part is sold individually.