After the rolling process the steel is very hard and rigid. Annealing makes steel more suitable for forming and bending. The steel is heated to a specified temperature for a sufficient period of time and then cooled down. An induction furnace can be used to raise the steel temperature. In this case, water or oil is used to cool the furnace coil and its rectifiers. Then the heated fluid is cooled down in a heat exchanger that on the other side of it the cooling water flows. The cooling of steel in annealing process is usually carried out either in the form of impinging gas jet on the surface or immersion in a tank of water or oil; if it immersed in a tank, heated fluid is pumped into a heat exchanger, and after heat transfer with cooling water, it returns to the immersion tank again.