It doesn't. It's just that those are the two ferromagnetic materials you're most likely to run into. A magnet will stick to nickel or cobalt just fine (note that US "nickels" are mostly copper, which isn't ferromagnetic).
No, your fingers cannot stick to a magnet. Only iron or steel objects will stick to a magnet. Your fingers do not have those materials, so it will not stick to a magnet.
the refrigerator is iron or steel, therefore the magnet sticks to it.
Magnet attract things made of iron nickel steel
Materials that contain iron ore. Iron, steel, tin, etc.
Magnets stick to iron cobalt and nickel
Not to pure tin. Magnets stick to things with iron in them.
Iron has magnetic properties and magnets will "stick" to it.
The magnets both have very strong energy there for connecting boths magnitude
Because of the steel (iron) used to manufacture the door.
Iron, steel
paper clip nail iron sand refrigerator staple
THey are stamped sheet metal and I would say they are a mild steel. Check it out with a Magnet; if the magnet sticks then it is definitely steel. If it doesn't then that does not stick that it could be an alloy with some iron in it.