Magneto-rheological (MR) fluid technology has been proven for many industrial applications like shock absorbers, actuators, etc. In this research, electrolytic and carbonyl iron powder based MR fluids have been synthesized and characterized to identify their different properties especially to suit high yield stress applications like MR brake, MR clutch etc. Few MR fluid samples based on sunflower oil, which is bio-degradable, environmentally friendly and abundantly available have also been prepared. Different synthesis and characterization techniques have been presented to help the researchers to work further in this area. characterization results of locally made MR fluid samples and commercially available Lord Corporation's 132DG MR fluid have been compared and then suitability of particular MR fluid for high yield stress application has decided.