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.ASME's standards are developed by committees of subject matter experts using an open, consensus-based process. Many ASME standards are cited by government agencies as tools to meet their regulatory objectives. ASME standards are therefore voluntary, unless the standards have been incorporated into a legally binding business contract or incorporated into regulations enforced by an authority having jurisdiction, such as a federal, state, or local government agency.