Ellipsoidal head (also called elliptical head or elliptical dish end) is usually made with Carbon steel, stainless steel, austenitic and non ferritic metals that can be cold worked. The shape of this ellipsoidal head is more economical, because the height of the head is just a fraction of the diameter. The elliptical dish end radius varies between the major and minor axis usually with the ratio is 2:1. The elliptical tank head is the economical solution for medium pressure tanks due to the reduced metal thickness requirement.