Elbow materials are cast iron, stainless steel, alloy steel, calcined cast iron, carbon steel, non-ferrous metals and plastics. 
the ways to connect with the pipe are: direct welding (the most commonly used way) flange connection, hot melt connection, electric fusion connection, threaded connection and socket connection, and so on. 
According to the production process can be divided into: welding elbow, stamping elbow, hot pressing elbow, push elbow, casting elbow, forged elbow, clip elbow and so on. 
Other names: 90 elbow, right angle bend, love bend, white steel elbow, etc.