Hex Flange Nut Factory Flange nuts are simply hex nuts with flanges, so it is called a hex flange nut, a washer nut, etc. The wide flange on the flanged nut acts as an integral washer, which distributes the pressure of the nut evenly on the part being fastened, reducing the possibility of damage to the part. In many cases, the flange nut is fixed, because there is a serrated flange under the...