The Hillman Group 43452 5/16-18-Inch x Locking Flange Nut, 15-Pack
Flange Nuts have wide flanges at one end that act as integrated, non-spinning washers. This serves to distribute the pressure of the nut over the part being secured, reducing the chance of damage to the part and making it less likely to loosen as a result of an uneven fastening surface. These nuts are mostly hexagonal in shape and are made up of hardened steel and coated with zinc.
