Flange bolts are identifiable by a ridge below the bolt head. This built-in washer distributes the clamping load over a greater area. Commonly used by assembly line workers in the automotive industry,Website:http://www.chinajinrui.net, these bolts are designed to provide the same holding power as a washer.A Flange Bolt is a method of connecting pipes, valves, pumps and other equipment to form apipework system.Flange bolts are usually screwed into such systems.Flange nut and the hexagonal nut size and thread specification is basically the same, just above the hexagon nut compared, it makes washers and nuts integrated, and in the following anti-skid tooth pattern, there is an increase in the nut and the workpiece surface area connected, compared to the common nut and washer combination, flange nut is more solid and has greater tensile strength.