Carbon Steel flange another layer means: according to the national standard requirements of the size, tolerance range and other production of flanges, different from non-standard size production of flanges also known as the Second Standard Flange (some people call non-standard Flange is incorrect) , usually some unscrupulous merchants will reduce the flange thickness, outside diameter two dimensions to achieve the goal of saving materials, there are scrap steel or angle materials processing Flange, usually this steel is the waste material whose chemical composition and mechanical properties are not up to standard. Even more, the Flange is produced by privately-made steel in the black steel works.
The outdated steel-making technology used in this privately-made steel making can not guarantee the mechanical properties and welding properties, it may not be able to be welded with the steel pipe, or the steel itself has cracks, blowholes, etc. .
So when buying flanges, try to choose carbon steel flanges.
