90 degree elbow, also called "90 bends or 90 ells", are manufactured as SR (Short Radius) elbows and LR (Long Radius) elbows. SR (Short Radius) elbows have a Center-to-Face dimension of 1.0 X diameter and are typically used in tight areas where clearances are an issue. LR (Long Radius) elbows have a Center-to-Face dimension of 1.5 X diameter and are the more common type and used when space is available and flow is more critical.

This is a fitting device which is bent in such a way to produce 90 degree change in the direction of flow of the content in the pipe. An Elbow is used to change the direction in piping and is also sometimes called a "quarter bend".

A 90 degree elbow attaches readily to plastic, copper, cast iron, steel and lead. It can also attach to rubber with stainless steel clamps. Available in many materials like silicon, rubber compounds, galvanized steel etc, they connect rigid or IMC circuit together to allow for 90 degree bends.

The main application area of an elbow (90 degree) is to connect hoses to valves, water pressure pumps, and deck drains. These elbows can be made from tough nylon material or NPT thread.