Carbon steel flange is a flange made of carbon steel material, also known as a flange plate, which is a fitting used to connect pipelines. The executive standards include the Ministry of Machinery standard JB81-94, the Ministry of Chemical Industry standard HG20593, and the national standard GB/T9119-2000. Common carbon steel flanges are made of materials such as Q235, 20 #, 16 manganese, and 45 # steel.