Flanged hex nuts are fasteners with threaded holes and broad flanges (outer ridges) that also fulfil the function of washers too. These nuts are designed with a hexagonal shape and are constructed with hardened steel and exterior coatings made of zinc.
The flange on the nut distributes pressure evenly over the part that is being secured, which prevents the object from loosening or being damaged during movement and rotation.
Flanged hex nuts are typically found in manufacturing assembly lines. They are used as single fastener mechanisms and speed up operations because the need for washers is eliminated. In the automotive industry, these nuts are used in door hinges and seat attachments.
Flanged hex nuts may be smooth or serrated on the inside: