This video lecture from Transition Elements (F.Sc. second year Chemistry) covers: Movements of dislocations and dislocation density and impurity atom percentage vs hardness and stregth of a material. Discussion of various properties and comparison between wrought iron , steels and the cast iron.details of puddling furnace for manufacturing wrought iron and how impurities like Si, C, P etc are oxidized and removed. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.