Magnetorheologic suspensions are specifically prepared mixtures of iron particles of about 10 micron with special stabilizing agents. The viscosity of such suspensions can increase by a factor of 100 with the growth of a magnetic field, while the viscosity of ferrofluids can only increase by 10-30%. This feature is ideal for application in magnetically operated brakes, sockets, dampers, vibration isolators, as well as in magneto-abrasive machining for polishing optical lenses. FerroLabs, Inc ...