A chamfer is a transitional edge between two faces of an object, often created at a 45° angle between two adjoining right-angled faces. It is sometimes defined as a form of bevel, but the two terms are not always interchangeable. Chamfers are frequently used in machining, carpentry, furniture, concrete formwork, mirrors, and to facilitate assembly of many mechanical engineering designs. They are used to ease sharp edges from a part, which allows parts in an assembly to fit together easily. Chamfers can also be used for aesthetic purposes as well as non-aesthetic purposes. Chamfering the edges of a metal bar removes the burr from the end of the bar, which can interfere with the function of a part. Chamfers can be made at any angle, but most chamfers connect two surfaces at a 45-degree angle. The primary purpose of a chamfer is to ease sharp edges from a part, which allows parts in an assembly to fit together easily.