[Carbon Steel]

A flange nut is a nut that has a wide flange on one end that acts as an integrated, non-rotating washer. This is to distribute the pressure of the nut over the secured part, reducing the risk of damage to the part and making it less likely to loosen due to an uneven mounting surface. The flange can be serrated to ensure locking. The serrations are angled to stop the nut from turning in the direction that would loosen the nut. Due to the serration, they cannot be used with a washer or on surfaces that cannot be scratched. The serration helps to avoid vibration of the nut and increase the holding force of the nut.