Aluminum extrusion angularity is defined as the feature angularity – the angle between adjacent extruded features. Many extrusions are >20′ in length. Typical angularity tolerances are +/- one to two degrees. However, many aerospace applications require +/- 0.5 degrees or less.
Higher tolerances can be achieved with indirect extrusion, however this process can not achieve the production rates of direct extrusion. In direct extrusion a billet is force into a die, and for indirect a die is forced against a billet.