Ferrite Bar Magnets

Affordable Ferrite Bar Magnets

Great for Educational Applications - Safe for Kids!

Ferrite Bar Magnets

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.

Educational Permanent Magnets

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.

 

Quaternary ammonium compound chemical structure

These Chrome Steel Bar Magnets are shown with their keepers. They complete the
magnetic "circuit". Like AlNiCo bar magnets, they are needed for long term storage.

 

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.
 

Science Classroom Ferrite Bar Magnets

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.
 

What Customers Say About Indigo Ferrite Bar Magnets

Some reviews on the 120mm bar magnet page:

  • The product is good and I want to buy more.-Wendy
  • I ordered these magnets to use for "polarity-confirming" on unmarked small spot-magnets that I use for my hobbies and for our healthcare disk-magnets. They work perfectly in those applications and are totally suitable for our purposes. Thank You for the great product and the great deal, Indigo!-Cat Daddy

 

Displaying 1 to 4 (of 4 products)
75mm (3") Bar Magnet

75mm (3") Bar Magnet

SKU: 33544
$0.35USD or lower Each
100mm (4") Bar Magnet

100mm (4") Bar Magnet

SKU: 33540
$0.45USD or lower Each
120mm (5") Bar Magnet

120mm (5") Bar Magnet

SKU: 33543
$0.95USD or lower Each
Bar Magnet Iron Filings Experiment for Kids

Bar Magnet Iron Filings Experiment for Kids

SKU: 33545-SP1
$23.95USD or lower Each
More Information

How to Visualize a Magnetic Field?

Here are 3 ways to use bar magnets for in a magnetic field visualization experiment. We offer material for the first two.

  • Make the magnetic field lines visible using iron filings with a petri dish or FieldView
  • Use a Mark II Magnaprobe to show that the magnetic field lines are above, below, side to side
  • Move a plotting compass around the bar magnet & watch the needle position change

What you are seeing over the bar magnet image shown below is analogous to the shape of the magnetic field around the Earth.

Magnetic Lines

 

Magnetic Field Superposition

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.

Overlapping Magnetic Fields

Additional Information

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.

Technical
Ferrite Cermaic Magnet Technical Specifications - C5 Grade
Grade Name Br (KG) HcB (KOe) Hci (KOe) BhMax (MGOe) Tmax
C5 3.8 2.4 2.5 3.4 250oC

Summary of Features

  • Economical-1/5th the price of AlNiCo
  • Strong-1/2 the strength of AlNico but does almost all the same experiments
  • No special storage requirements-won't fade with age
  • Use for repulsion-attraction; won't demagnetize when pushed together
  • Stamped "N" & "S" & painted red & blue respectively
  • Paint has low lead & heavy metal levels (77mg/kg=77ppm; less than govt. regs.)
  • Will pick up minimum of 20 uncoated metal paperclips
  • Note: Ferrite bars are brittle & will chip if dropped on hard surfaces

References

  1. Grades of Ferrite
  2. Grades of Alnico
  3. Government Regulations for Lead Paint (90ppm max)
     
Instructions/Safety

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.