Creative Hobbies 29 Piece Strong 1.25 Inch Round Ceramic Ferrite Ring Magnets, With 3/8" ID Center Hole x 3/16" thickness, Universal Use on Refrigerator, Whiteboard, Arts Science Project, Crafts

I was looking for really strong magnets to use for my Science classes and these were perfect for our magnetism activity

These magnets are great! They are really strong. My pictures show the North to North with me only holding one with 1 finger and I had to press down to control the magnet. I would say be careful when pulling them apart and putting them together. They can pinch you and it does not feel nice. Also, when reversing them (south to south or north to north) the reverse polarity is so strong that it will flip the magnets so they can be together again :) The magnets will distribute a small amount of the black matter onto you hands or whatever it touches if you are not careful. Only some of them do this. However, a little rinse and that problem is solved. They dry very quickly, but, I would suggest that wiping the bottom dry if you plan to just lay them out. I understand that many people know how magnets work. However, there are those who do not the little things so I am just giving the information so those people will know.

Strong fingers can't pull them directly apart, you'll need to slide them off one another. Stack them alternately on a pencil and they'll stay an inch apart. These are perfect for explaining magnetism to students.

I ordered these magnets to use in the classroom for an activity. One of the magnets began chipping and about an 8th of it chipped off. I used these with older students and they are careful, but I would be wary to use these with younger students.

center hole fits a 1/4 inch square dowel and slides well. They will stack on the dowel as a spring, floating above each other. Cheap enough to break one and show kids how a magnet itself wants to fly apart, not pull itself together. The pieces will want to flip so N meets S rather than 'heal the fracture'.