Elbows, which are formed by stamping a flat blank of the same material as the pipe into a half-ring shape, and then welding the two half-ring elbows together. Due to the varying welding standards for different types of pipes, they are typically shipped as semi-finished products with spot welding fixed in pairs, and the actual welding is performed on-site based on the pipe weld grade, hence also known as half-welded elbows.