A hex flange bolt is characterized by its hex head along with a circular flange underneath, serving like a built-in washer. The flange spreads the clamping force of the bolt over a greater area, reducing the possibility of loosening due to vibration. This structural feature not only secures the bolt in a more effective way but simplifies assembly and has thus favored its use by profes... https://www.dalloyedbolts.com/hex-flange-bolts-manufacturers-suppliers-stockists-exporters.html