Elbow, made by stamping a flat piece of material identical to the pipe material into a semi-circular shape, and then welding the two semi-circular pieces together to form a complete elbow. Due to varying welding standards for different types of pipes, the semi-finished products are typically fixed with spot welds at assembly points before leaving the factory. The actual welding is performed on-site based on the pipe weld quality grade, hence also known as a two-piece welded elbow.