Ferrite bar magnets for basic experiments on magnetic field lines, attraction-repulsion, compass readings & more.
Child safe-our Certificate of Analysis guarantees no heavy metals in paint used for easy to identify opposite poles.
Buy the right magnet for your school & science project educational needs-buy Indigo ferrite bar magnets for performance & economy.
Chrome steel bar magnets were the class standard up until about 20 years ago. They had a number of disadvantages, however. They had to be stored with "keepers" (metal plates) & demagnetized easily if dropped or if one were used to repel another. They were largely displaced by stronger, more durable & cheaper AlNiCo (aluminum-nickel cobalt) made in Asia.
Neodymium magnet bars are much stronger, more expensive & are not magnetized lengthwise general. They are also brittle but are well suited for teaching applications such as for magnetic braking or various hobbies, crafts & 3D printing.
Indigo ferrite ceramic bar magnets are grade C5, painted blue-red & stamped to indicate their north & south magnetic poles. The N-S and magnetized at the ends for repulsion-attraction. This grade is about 1/2 the strength of typical Grade 2 AlNiCo bars & typically 1/5th the price per bar (compare our 75mm bar magnets to 3" AlNiCo). Their only disadvantage is being more brittle; fair trade off considering the cost difference.
Ferrite bar magnets are just the right strength for hands-on experiments. Teachers can readily demonstrate the shape & presence of magnetic fields with compasses, iron filings or Magnaprobes. See also our video that uses Lego to build a magnetic test track to show force & motion. They also pass the paper clip test.
This makes them suitable for all grades and homeschooling with no special storage requirements needed. They are child safe as guaranteed by our Certificate of Analysis.
Some reviews on the 120mm bar magnet page:
Here are 3 ways to use bar magnets for in a magnetic field visualization experiment. We offer material for the first two.
What you are seeing over the bar magnet image shown below is analogous to the shape of the magnetic field around the Earth.
Put two bar magnets, as NS-NS (or SN-SN) under a petri dish. Sprinkle some iron filings over the ends of the magnets & the gap in between. Then move them towards each other & back. You should see similar magnetic field lines form in what is called superpositioning or vector addition of their respective magnetic fields.
Our blog, Ferrite Bar Magnet Experiments for Kids has additional suggestions for using bar magnets.
You can watch an older, pre-HD video of the magnaprobe in action & how it illustrates the 3D nature of magnetic fields; a great analogy for the Earth's magnetic field.
|Ferrite Cermaic Magnet Technical Specifications - C5 Grade|
|Grade Name||Br (KG)||HcB (KOe)||Hci (KOe)||BhMax (MGOe)||Tmax|
These magnets are very weak so there is no danger from 2 of them coming together in an attraction experiment. There are also safe for young children, supervised of course. You can view this report on Paint Analysis that shows the levels of heavy metals are well below recommended limits.