I'm trying to figure out what kind of ring magnets repel on both sides. That is, if I place one around a pencil and a second around the same pencil, they will always repel regardless of which side is up.
Before you try to tell me they don't or can't exist, let me assure you that I know they exist. I played with a couple of them as a kid at my grandfater's house. He passed away some time ago and I don't know what happened to the magnets, so now I'm trying to figure out what they were (and get some, if they are available somewhere). I have no idea what the magnetic field looks like around one of these, but plan on figuring it out if I ever get my hands on some (assuming there isn't already an explanation online somewhere that I haven't found yet).
The specific magnets that I handled were about 1.5 inches in diameter with a large center hole. They were shaped somewhat like a doughnut. That is, they were not flat like regular ring magnets and the cross section was a polygon (octagonal, if I remember correctly). The only way I recall the magnets attracting one another was diagonally (i.e., imagine placing two on a flat surface near each other and raise the edge of one up and on top of the other so that they are barely overlapping).
My grandfather had a lot of weird stuff that came from industrial sources and I seem to recall that these magnets may have been used in power or telephone applications in some way, but I don't know exactly how.
I've searched online and have been unable to find anything to help me identify these magnets. Any help is appreciated.