An Elbow is installed between two lengths of pipe or tubingso that the flow direction can be changed, usually a 90° or 45° angle; 22.5° elbows are also available. The ends may be machined for butt welding, threaded (usually female) or socketed. When the ends differ in size, it is known as a reducing (or reducer) elbow. They are available in various grades of brass and bronze and made in various sizes. They are forged for the smaller sizes and cast for the larger one. All kinds of threads can be provided as per the needs of the customer.