I was playing around with ferrous magnets and neos and noticed a huge difference in both strength and distances in the fields from the magnets. The neos are about the size of American quarters (coins). The ferrous magnets are the 3 for 99 cent flavors from the hardware store, each about 1.5 inches long. The neos are stronger. The ferrous magnets are considerably cheaper, but the magnetic field of ferrous magnets extend out about 4x as far. Why the big differences in field distances?