Posts belonging to Category Magnets in General

Understanding Magnet Myths & Facts

Magnet myths and facts

When it comes to magnets, there’s a lot of information and misinformation out there.  And it can be hard to separate fact from fiction.  Here’s the top five magnet myths we find ourselves explaining regularly.



1. Magnets erase your hard drive.

It's a magnet myth that a magnet will erase your computer hard drive.

To explain this, it’s important to note there are two types of drives – solid state drives and hard disk drives.  Traditionally, hard disk drives (HDD) create binary code by changing the polarity of the magnetic bits.  So, in theory, a magnet would flip the bits and effectively erase any data stored on the HDD.  Unfortunately, the strength of magnet needed to accomplish this feat is equal or greater to that of most MRI magnets, or 1.1 Tesla¹.   Solid state drives (SSD), for example USB thumb drives, smartphone memory, and some laptops keep binary code in a stored charge. No magnetic field needed.  In this case, a magnet poses no ability to affect the stored data on SSDs.

It’s a magnet myth.


2. You can order a monopole magnet.

If we remember our science classes, we recall all magnets have a north and south pole.  If you cut a magnet in half, you simply have a smaller magnet with two poles.  These are called dipole magnets and is how magnetic material is found naturally.  While we manufacture magnets with more than two poles (this commonly how flexible magnetic sheeting is magnetized), it isn’t currently possible to provide a magnet with just one pole.

Confusion over single pole, or monopole, magnets stem from multiple sources.  First, some magnets are sold labeled as north or south – which isn’t to say they are monopoles.  These magnets simply have a particular pole facing out, with the opposite pole covered with adhesive or surrounded by a metal or plastic cup.  Some applications require a north/south magnetic selection, where it is important to match the poles correctly.  Another reason for confusion stems from marketing terminology.  A Google search for ‘monopole magnet for sale’ yields 61,000 results.  None of these magnets are actually monopole magnets.  Rather, they are the same magnets and magnetic assemblies sold as basic dipole magnets.

However, recent groundbreaking research led physicists to create a synthetic magnetic monopole under extreme conditions in a laboratory².  This paves the way for future potential breakthroughs, despite the fact that no observation of a naturally occurring magnetic monopole has been identified.

It’s magnet myth – for now.


3. Magnets are positive/negative.

If you think of a traditional image of bar magnet, half red and half blue, then it might be easy to understand why some people interpret north and south poles as positive and negative.  But, in reality, permanent magnets don’t have a positive or negative charge.  They have two consistent magnetic fields, or dipoles.  Currently, there are no monopole magnets.  By nature, an electrical charge is either positive or negative and can exist without its opposite.  Because an electrical charge is referred to as a monopole and magnet cannot be monopoles, positive and negative magnets don’t exist either.

It’s a magnet myth. 


4. Magnets will damage my cell phone.

In this case, it’s mostly a myth.  We can refer back to our first myth for the science (magnets won’t damage the phone’s memory).  However, magnets have the potential to impair the phone’s internal compass.  Fortunately, most magnets simply aren’t strong enough to cause a problem – even neodymium magnets.  It takes a larger rare earth, or neodymium magnet to interfere with the internal magnetic sensors or to lightly magnetize internal steel components. Just think about how many cell phone cases, holders and accessories feature magnets to understand how confidently magnets are used in close proximity to cell phones. However, since we love our maps and apps, we don’t recommend rubbing industrial strength magnets all over your phone!

It’s mostly a magnet myth.


It's a fact that a magnet can demagnetize the magnetic stripe on the back of credit cards.

5. Keep magnets away from credit cards, gift cards and hotel keys. 

This is one magnetic fact that is rapidly changing with times. The black stripe on the back of most cards is referred to as a magnetic stripe. So it’s logical that the stripe can be erased, or even partially scrambled, by coming in contact with a magnet.  An article by Cynthia Drake at details exactly how simple it is erase that black stripe with nothing stronger than a refrigerator magnet.  However, not all magnetic stripes are created equal.  The coercivity of a typical credit card is high, meaning it is takes a little more work to demagnetize the strip.  Hotel keys possess a lower coercivity meaning making them much more susceptible to demagnetization.  BUT, with the advent of the RFID chips, magnetic strips soon may be irrelevant. Permanent magnets have no effect on RFID chips.  They won’t erase, block or scramble the card’s data.

It’s a magnet fact – for now.


While many of our old magnetic beliefs stem from the days of old technology, like CRT and floppy disks, others failed to keep up with cutting edge research.   Turn to our expert sales team to for help deciphering any magnet myths you run across.






Viewing Magnetic Fields and Identifying Magnetic Poles

Typically, magnetic fields are invisible.  It’s one of the things that adds to the mystique and curiosity of magnets.  Bust visualizing magnetic fields and identifying magnetic poles can be done with just a few simple tools.


Magnetic Fields

Viewing magnetic fields with with viewer film

Magnetic Viewer Film shows the multiple poles present in flexible magnetic sheeting.

There are a few ways to detect magnetic fields, one of the most reliable is with magnetic viewer film.  This unique film suspends tiny nickel particles over a thin layer of viscous material allowing the particles to align with magnetic fields.  It shows the location, as well as how many poles, a magnet has.  Simply place the sheet over the magnet and the poles appear as dark areas. The light green areas are the magnetic fields.

Magnetic viewer cards and sheets allow users to:

  • Pinpoint location of magnetic poles
  • Determine number of poles a magnet has
  • Easily find ‘hidden’ magnetic fields



Make it Yourself

While viewer cards quickly illuminate poles, a simple DIY project illustrates magnet flux in motion.   To make one, just a few simple items are needed.   Start by gathering the materials:

  • a clear bottle
  • mineral oil (or other viscous fluid like glycerin)
  • iron filings
  • assorted shapes of magnets

See magnetic fields when you make your own magnetic viewer bottleCarefully pour the oil into the bottle or container of your choice.  Add coloring, if desired, and shake gently.  Next add in iron filings.  The amount added depends on the bottle size, but in order to see the iron particles moving, don’t add too much metal.  At this point, all that is left is to cap the bottle and shake the contents.  Rubbing a magnet along the outside of the bottle draws the metal filings along the magnetic field lines. Using different shapes of magnets fully illustrates magnetic flux.

A few tips: Use a viscous fluid like mineral oil or glycerin to suspend the iron filings.  Water is not well suited for this use.  Iron filings, iron oxide or cut up pieces of steel wool all work to demonstrate the pull of the magnet.  Easily purchase any of these supplies at local discount stores.

This project is excellent for demonstrating the magnetic field in motion and is ideal for educational purposes.  And, it’s just plain fun!


Identifying Magnetic Poles

While magnetic viewer cards show the location of magnetic poles, they don’t classify the pole.  If determining a magnet’s north or south pole is important, then the tool to use is a pole finder.

Identify magnetic poles with pole finder

This basic magnetic pole finder identifies the north or south pole of a magnet. An electronic version, beeps when then the pole is found and lights up red or green for pole indication.

Pole finders are very simple to use.  Just touch the tip of the pole finder to the surface of the magnet and S or N appears in the window.

Pole finders are useful for:

  • Verification of product assemblies
  • Quality control
  • Manufacturing applications
  • Education


With science fair season in full swing, both magnetic viewing film and pole finders make useful tools for a variety of experiments.  Master Magnetics offers several different types of magnetic viewing film and pole finders.  For more information about identifying magnetic fields, contact our sales team.

Attractive Prevention- Why Choose Cow Magnets

Prevent hardware disease with cow magnetsIf an ounce of prevention is worth a pound of cure, then one cow magnet is certainly worth its weight in, er, steak.  Popular with farmers, ranchers and veterinarians, cow magnets are a well-known method of preventing hardware disease in cattle.


About Hardware Disease

The University of Missouri extension office estimates between 55 and 75 percent of cattle in the eastern United States have some type of hardware in their stomachs.

Because cows don’t discriminate when it comes to their food, they easily eat pieces of metal with their feed or when grazing.  The metal makes its way to the cow’s reticulum (or second stomach). Here it can puncture the stomach wall, developing into an infection or damaging other organs.  This is referred to as hardware disease, hardware stomach or, more rarely, tire wire disease.

Also medically known as traumatic reticulo-peritonitis or reticulo-pericarditis (depending on the location), hardware disease causes loss of appetite and decreased milk output in dairy cattle and ability to gain weight in feeder stock.  In some cases, administering a cow magnet might attract the offensive metal and pull it back into the stomach.   But treatment often involves exploratory surgery and antibiotics.  Prevention is key to avoiding hardware disease.


Locating the Risk

Decades ago, the primary culprit of hardware disease came from bailing wire.  As bailing wire has fallen out of use for this exact reason, metal still finds its way into feed in the form of roofing nails.  Additionally, bits of fencing wire and other metal ‘junk’ gets chopped up in balers and feed choppers.

Other sources of contamination comes from blades and other parts of machinery wearing out and falling into choppers.  Also accidentally allowing grazing in areas typically prone to litter or junk can lead to digestion of metal.


Prevention with Cow Magnets

Choose cow magnets because they work

Simple Attraction: Cow magnets do their job by catching metal items and preventing them from doing damage.

Magnets play two roles in preventing hardware disease.  First, use of heavy duty magnets on feed trucks or conveyors acts as a first line of defense to catch any rogue metal as it passes through the equipment.

Second, many veterinarians recommend cow magnets.  Often given after calves are a year old, cow magnets need only be administered once in the bovine’s lifetime to effectively hold ferromagnetic object in the reticulum.

Since cow magnets act as a preventive measure to hardware disease, they save farmers and ranchers the added expenses of:

  • veterinarian bills,
  • loss of milk output,
  • decreased breeding opportunities and,
  • potential death of the livestock.


Master Magnetics provides cow magnets different types, including the patented Ru-Master 5™.  For more information about choosing cow magnets, contact our sales team or click here to purchase online.



Gluing Magnets: Three Tips for Avoiding a Sticking Situation

Gluing magnets doesn't have to be difficult

Gluing magnets can be one sticky situation – and not just literally.  It’s tricky to make sure the magnet stays where it’s attached, not where it’s attracted.  We’ve found when it comes to adhering magnets, there are three key steps to creating a successful bond: preparation, selection and cure time.



It’s often overlooked, but surface preparation is makes a significant difference in achieving a strong surface bond between a magnet and the adhesive.  Make sure the surface of the magnet is dirt and oil free by wiping it with rubbing alcohol.  Magnets with smooth nickel coatings, like neodymium magnets, typically need some abrasion to improve adhesion.  A quick swipe with a fine grit sand paper does the trick.  Of course, be sure to clean off any residual dust.  Taking a few minutes to prep the magnets can save hours of headaches down the road.



If you’ve been to the store to purchase adhesive recently, then you know the selection can be overwhelming.  But choosing the correct adhesive is critical. There are several excellent options available, and selecting the right adhesive depends on the material you are affixing the magnet to.

For most surfaces, such as metal and wood, the typical strong adhesives such as two-part epoxies, Loctite, Liquid Nails, Super Glue, and Gorilla Glue all work well.

For craft projects with light-weight magnets, double-sided tape and Glue Dots hold just fine.  Low temp hot glue can be used with ceramic magnets – but not with neodymium magnets.  The temperature of the glue can lower the strength of those magnets.

Plastics pose the most challenging surface to attach a magnet to.  Choose an adhesive specifically designed for plastic.  Both 3M, E6000 and Loctite make excellent choices.

As a point of reference, one of the adhesives we use on our neodymium magnets is a Low Surface Energy foam tape from 3M, making it effective for plastic surfaces.


Cure Time

This last step is the hardest – we all want to test our projects or speed up manufacturing, but none of the preparation and gluing matter if you rush right into use.  Giving the adhesive proper time to cure is the last step in ensuring the bond holds tight.  Follow manufacturer directions to determine this time.   Keep in mind that high humidity environments and excessively thick applications of adhesive both slow down cure time.

For our own magnets with adhesive, we recommend 24 hours cure time.


Because we understand the importance of adhesive, we offer some of our magnets with a pre-applied adhesive. In our next blog, we’ll delve into details the pre-applied adhesives on our flexible strip and sheeting and how to achieve successful results with these adhesives.


Do you have any other tips you’d add? Let us know in the comments below.

Science Fair Projects Featuring Magnets

Magnets make a fascinating topics for science fair projects,  as well as illustrating many basic principles of science and generating downright fun experiments.

As science fair projects begin in earnest, here is a collection of some of the best science fair projects or experiments involving magnets we’ve seen.


Illustration of the cross-sectiion of what a mag-lev train looks like.

Illustration from Science Buddies.

 1. Magnetic Levitation- Maglev trains have been big news in the past year. Explore the science behind the future of mass transit with basic (or not so basic) magnet levitation experimentation. Simple experiments show how magnets levitate using their repelling force. Science Buddies details a great experiment building a small maglev train. More advanced students can also build propulsion mechanisms with the train, or measure how other variables like temperature, weight and material selection affect the motion.


2.  Electromagnets- Homopolar motors are the simplest electric motors generating rotational movement; and are simple to create with basic components and magnets. In this link, see how to make a simple car using just a basic AA battery, two rare earth magnets and some foil. Other versions of this project include shaping wire to spin, or adding a screw or bolt into the configuration. Regardless of the setup, these experiments are excellent introduction to electromagnets and motors.


Photo of a science fair project or experiement where a magnet is hovering over a bag of cereal and pulling the iron to the top.

Can you stomach this experiment? Photo from Steve Spangler Science.

3.  Eat Iron – This simple experiment is visually amazing, involves searching out iron in ‘iron fortified’ food and might require a strong stomach. Cereals, and other iron-fortified foods, really do have iron added to their recipe, making them healthier for many. In this experiment, dissolving the cereal in water lets students see the exactly how much iron could be consumed as the magnet pulls the element away from the food. Compare types of cereal, breads, pastas, or snack bars. Visit Steve Spangler Science for more information on this experiment.


4.  Lenz’s Law – Explore Lenz’s Law with a stop watch, various thicknesses of copper tubes and magnets. This is a YouTube favorite, and for good reason – it’s a strong visual representation of eddy currents as they relate to a magnetic field. details a basic experiment, which can be expanded to add different materials, thicknesses of materials and strengths of magnets. Watch a video detailing this here.


These experiments can all be done with materials – including the magnets – found at your local hardware store or craft store. In some cases, complete kits are available from educational suppliers. If you’re looking for assistance with types of materials needed, our magnetic products specialists are available to assist.

If you, or your favorite student, has a magnetic science fair project or experiment, share the experience with us!

Magnetic Road Sweepers are the Right Tool for Emergency Access

TYMCO® utilizes Magnet Source® Sweepers for Road Clean-up after Fertilizer Plant Explosion in Texas

There are so many factors involved with providing an effective response to an emergency situation. Having the right tools and equipment is always part of a successful solution.

TYMCO, Inc. is a manufacturer of Regenerative Air Street Sweepers located in Waco, Texas, about 19 miles south of West, Texas. When the fertilizer plant located in West exploded on April 17, 2013, TYMCO volunteered to bring their expertise, equipment and the needed sense of urgency to get the job done right and quickly.

Magnetic road sweepers from Master Magnetics works to clean up road in Texas after the explosion.

“The situation was that emergency vehicles were having difficulty gaining access to the necessary areas because of all the debris scattered across the roads,” said Gary Young, Vice President, Engineering for TYMCO. “The first priority in our cleanup role was to clear the roads of all hazardous debris. We have a large selection of road cleanup equipment to handle any size task. We chose to go with the Magnet Source® 84” and 96” Hanging Magnetic Sweepers because of the need for speed and simplicity. We did not have time to install our larger electrically actuated magnetic sweepers, so we chose to hang these off our big International Trucks and go,” Young explained. (The Magnet Source® brand is a trademark of Master Magnetics, Inc.).

A hanging magnetic road sweeper from Master Magnetics in use.

“Our initial process was to have three to four people walking along with our street sweeper trucks, tossing large-size debris into the street sweeper, and periodically clearing off magnetic sweeper. The magnetic sweeper protected our trucks’ tires so we could proceed with cleaning up the rest of the debris,” Young added.

Hanging magnetic road sweepers are available in widths from 18 to 96 inches from Master Magnetics. The Magnet Source® sweeper product line also includes push-type and trailer-type magnetic sweepers. These magnetic road sweepers are super-powered, permanent magnets for the removal of sharp iron objects from roads, parking areas, loading docks, runways and other important traffic areas. Hang-type magnetic sweepers greatly reduce the possibility of costly flat tires and injuries caused by nails, scrap iron particles, staples, etc. Two eyebolts are installed on each magnet for suspending from vehicles.

Simply hang a magnetic sweeper from your forklift or vehicle bumper and “sweep” all contaminated areas. The sweeper hangs approximately two to four inches off the ground, and maximum operating speed is five mph. To clear collected debris, wipe the face of the magnet with a glove or heavy shop towel. There are also magnetic sweeper models available with quick-release handles for the easiest removal of collected debris.

Unique P.O.P. Display Features Best Selling Magnets at National Hardware Show

Master Magnetics’ Mini Sweeper™ and Pick-Up Pal™ displayed in functional and space-saving design

Master Magnetics, Inc. will feature their two best selling items, the Magnetic Mini Sweeper™ and the Magnetic Pick-Up Pal,™ in a new functional, space-saving end cap display at the upcoming National Hardware Show in Las Vegas, booth 7219.

Sidekick Combo Display

The new metal fixture is an innovative, permanent display for the Mini Sweeper™ and Pick-Up Pal™ that attaches to the end of store gondolas. The durable and long-lasting display comes with attention-getting, four-color, trilingual side panels. The Sidekick Combo Display makes the most efficient use of space on gondola fixtures without full end cap shelving. It’s ideal for stores with limited floor space. The metal fixture holds four Mini Sweepers™ and six Pick-Up Pals™ and mounts centered or to either side on the slotted gondola standard.


The 15” Magnetic Mini-Sweeper™ (MSRP $29.35) and Pick-Up Pal™ (MSRP $23.05) are the ideal lightweight tools for removing hazardous metal debris such as nails, screws, bolts and metal scrap from areas in the garage, home, workshop or outdoors. The Magnetic Pick-Up Pal™, with a pull strength of 65 lbs., is also great for retrieving tools or metal objects from hard-to-reach areas.

Retail-Packaged Magnets

The Magnet Source™ brand is a proven profit center for retail markets with over 250 SKUs, trilingual packaging and customized planograms. The complete line includes retail-packaged magnets for Hardware, Home Improvement, Automotive, Craft, Hobby, Office/School Supplies and Housewares categories. The Magnet Source™ magnets are available at local and national retailers throughout North America.

Pole Shift Forces Airport Makeover


WFLA’s Brooks Garner reports on the pole shift.

Alan Boyle writes: Don’t think of this as another sign of the apocalypse, but Earth’s magnetic north pole has been shifting enough that Tampa’s airport has to repaint the numbers on its runways.

Tampa International Airport in Florida has closed its primary runway until Jan. 13 to change the numeric designations at each end, as well as the signage on taxiways leading to the runway. The Tampa Tribune said the runway had been designated 18R/36L, indicating its alignment along the 180-degree approach from the north and the 360-degree approach from the south. Now the numbers are being revised to read 19R/1L (190 degrees and 10 degrees). Two other runways will be closed later this month for a similar signage change, the Tribune reported.

The changes are required by the Federal Aviation Administration, which wants the numeric designations to reflect magnetic-north headings to the nearest 10-degree increment.
For decades, the magnetic north pole has been migrating from Canadian Arctic territory toward Russia. That shift has accelerated in recent years, and current estimates suggest that the pole is moving at almost 40 miles a year. Maps from Natural Resources Canada chart the movement since 1831 and project the trend through 2050. Movements in the magnetic poles are caused by the motion of molten iron at Earth’s core, which serves as the planet’s magnetic dynamo. Here’s how NASA explains the process.

Airports generally change their runway designations every few decades, depending on how the pole shifts shake out numerically. For example, Stansted Airport in the London area renamed its 23/05 runway as 22/04 in July 2009 to reflect the magnetic shift. “It’ll roughly be another 56 years before we have to consider changing it again,” Trevor Waldock, head of airside operations at Stansted, told the BBC at the time.

A catastrophic pole shift is one of the oft-used plot devices in doomsday tales — and some of the doomsayers have tried to link the phenomenon to the 2012 Maya apocalypse. Earth’s magnetic poles have been known to reverse themselves every 400,000 years or so, in a process that’s outlined in the video above.

This NASA Web page explains that the shift in the magnetic poles, or even a pole reversal, need not be feared. “As far as we know, such a magnetic reversal doesn’t cause any harm to life on Earth,” NASA says. But a lot of runway numbers might need to be repainted.

Can a Magnet Really Make Your Credit Card Not Work?

NOTE: Master Magnetics, Inc. cannot confirm or refute the findings of this article. We simply provide this in the interest of our website viewers.

Written by Cynthia Drake, provided by

Will your credit card become unreadable if it’s exposed to magnets? In a previous story, we said yes, but many of you begged to differ. Seeing that, we took the challenge of clearing things up once and for all.

The result: With the help of a junkyard magnet, a garden–variety refrigerator magnet and a professor with a vast knowledge of magnetics, we were proved right –– eventually.

A highly charged debate ensued after our “How to destroy a credit card” was published in September of 2009. Folks started weighing in on whether magnets –– especially those of the refrigerator persuasion –– actually had the power to strip a stripe. “Running a magnet across the strip will do nothing,” said one commenter on our video at Others chimed in with their own experiences with credit cards and magnets.

So we put our cards to the test against a barrage of different magnets, even heading to the junkyard to swipe stripes with some serious electromagnetic forces.

But before we get to the results, let’s take a step back.

The Mystery of the Stripe

Credit card magnetic stripes carry more than just your precious financial data; they carry some mystery, too. The stripe you see on the back of your card is a collection of magnetic particles –– each a very small magnet about 20 millionths of an inch long. It’s a commonly held belief that exposure of these particles to an external magnet can scramble the information and make the card unreadable.

That’s the theory. But does it really happen? We sought to find out.

Magnets on a Mission

Our experiment began with three different magnets of various strengths:

• A generic refrigerator magnet, similar to the one that’s probably holding up your kid’s artwork in your kitchen.

• A slightly more powerful magnet, which is capable of holding up to 72 pounds.

• A junkyard magnet, which can hold about 7,000 pounds and is also just plain fun to watch in action.

You never know when you’ll just happen to be waving your credit card around in a junkyard.

We swiped three separate cards –– all were tested and functioning properly before the experiment, by the way –– with one of these types of magnets; then took them to a local retailer who ran each card through a credit card machine to test which ones were still readable and which ones weren’t.

Once all preparations were in place, it was time for the big reveal.

Moment of Truth

Up first was the card exposed to the fridge magnet. It turned out that it was still readable by a credit card machine. The second, larger magnet was not, despite multiple swipes. Could we have been on the way to the major scientific breakthrough we’d been hoping for?

Not so fast. It was time to put the third card, the one exposed to the junkyard magnet, to the test –– and surprisingly, the card was still readable. It had survived the most powerful magnet in our arsenal.

This caused considerable confusion. Our initial assumption was that the strength of the magnet would play a role in the demagnetization process. Thus, a wimpy refrigerator magnet wouldn’t have the data–destruction powers of a gigantic junkyard magnet.

We were wrong.

Puzzled, we turned to an expert for answers.

Calling In the Expert

Totally stumped by the fact that just one out of three magnets (the one of medium strength) had rendered a card unreadable, we sought out the guidance of A. Dean Sherry, a chemistry professor at the University of Texas at Dallas.

Sherry is also associate director of the Rogers Nuclear Magnetic Resonance Center and a radiology professor at the university’s Southwestern Medical Center. In other words, he’s got plenty of magnetic experience for our purposes.

He heard us out and politely corrected our assumption about the relationship between the strength of the magnet and its power over the data on the stripe. “The field strength isn’t all that important,” he said. “Even the refrigerator magnet should work eventually.”

So what was the deciding factor? Exposure time.

“It is well known that magnets will wipe out information on credit card stripes,” Sherry said. “However, it doesn’t always happen after one exposure. It may take several exposures for the card to be deactivated, but it will happen eventually.”

Huh. So armed with that information, we decided to replicate the experiment with the refrigerator magnet. We left the magnet exposed to the credit card stripe for several minutes and took a few more swipes for good measure.
Then we took it back to the store and … success. The card’s stripe had been demagnetized.

Not the Only Way to Destroy a Card

The safest, most practical way to destroy your credit card, however, is to cut it into tiny pieces using a shredder or a pair of scissors.

For an extra level of protection (or if you just want to replicate our very cool experiment), you can use a magnet on the stripe. Just be sure to expose it for a significant amount of time –– that goes for heavy–duty junkyard magnets, too.