We all use magnets in our daily lives, but do we really pay attention? When you switch your mobile phone to vibration mode, the quick motion and the corresponding sounds you hear as a result are caused by a tiny neodymium magnet inside the phone. If you're a teenager or a big fan of high-tech gadgets or music addict, I'm almost sure you have the latest headphones, but do you know that the excellent sound quality and full bass range are enhanced by neodymium magnets? Yes, that's one of the applications of neodymium magnets.
Can magnets damage electronics?
Strong magnets can damage electronics or erase data from data storage devices. However, not all types of data storage and electronics are susceptible to the effects of magnets.
What can and cannot magnets do?
Neodymium magnets do not affect:
- USB drives,
- SD cards, SSD drives
- CDs, DVDs (optical storage),
- cameras (VHS tapes from cameras YES!),
- digital cameras (MMC memory cards),
- smartphones, tablets - some (without compass)
Neodymium magnets can erase data, so keep them away from:
- credit cards,
- other magnetic cards (loyalty cards, gift cards, hotel cards),
- HDD hard drives (magnetic storage),
- old VHS tapes (magnetic storage),
- audio cassettes (magnetic recording)
Neodymium magnets can damage:
- cell phones, tablets (though data cannot be erased),
- mechanical watches,
- CRT and LCD monitors, televisions (old cathode-ray tube type),
Cell Phones, Tablets
Cell phones and tablets should function properly even after being exposed to strong magnets. Magnets will not erase data stored on a cell phone or tablet. However, magnets can interfere with the built-in compass found in many cell phones.
The magnetic field produced by neodymium magnets is much stronger than the Earth's magnetic field in their vicinity. Therefore, a cell phone placed near a magnet will point north towards the magnetic field line, not the geographic North Pole:
The problem can arise if a strong magnet magnetizes the metal parts of a cell phone and they partially retain their magnetization even after removing the magnet. Then, the compass no longer works. The built-in compass feature is used by various GPS applications and Google Maps, which rely on the compass to determine the orientation of the cell phone. A tablet with a built-in compass may react similarly to magnetic fields.
If you don't have a compass in your cell phone/tablet, magnets should not affect it.
Data on all magnetic cards can be erased by coming into proximity with magnets.
However, there are two types of magnetic cards:
- HiCo - cards more resistant to magnets. This includes all credit and debit cards that have a dark brown or black magnetic stripe. To damage them, a magnetic field with an intensity of ~400 gauss is required (safe distance is ~50 mm).
- LoCo - cards less resistant to magnets. They are used in loyalty cards, gift cards with credit or hotel cards, and have a light brown magnetic stripe. To damage them, a magnetic field with an intensity of ~30 gauss is required (safe distance is ~150 mm).
HDD Hard Drives (Magnetic Storage)
It is possible to erase data from a hard disk drive (HDD) using an extremely strong neodymium magnet if it is moved across the surface of the hard drive. However, it should be noted that there is no guarantee that any data will be erased even then. Hard disk drives themselves contain strong neodymium magnets. To damage them, a much stronger magnet would be required. Placing a neodymium magnet on the surface of a computer HDD does not always damage the hard drive. Using a magnet to remove data from a hard disk drive is not always a reliable method.
Old Video Tapes and Audio Tapes
Data on tapes can be easily erased using magnets. If you want to quickly erase a recording on a tape, simply touch it gently with a neodymium magnet:
To prevent data loss on old VHS tapes, keep them at least half a meter away from small magnets and one meter away from large neodymium magnets.
A strong magnetic field can magnetize the metal parts of a watch, such as the spiral spring. It is then attracted to other metal parts of the watch, which can slow down or speed up its oscillation. Most modern watches meet the ISO 764 standard and are resistant to a magnetic field of 60 gauss. Other watches may be more sensitive to magnets, but the more expensive the watch, the more resistant it is to magnetic fields. If your watch stops working after exposure to a magnet, take it to a watchmaker. They can demagnetize them reversibly using an alternating magnetic field.
A strong magnetic field can switch an implanted pacemaker into a test mode and temporarily affect its operation. People with implanted pacemakers should avoid strong neodymium magnets as well as strong electromagnetic fields, as they can interfere with the pacemaker's function.
USB Drives, SD Cards, CDs and DVDs, Cameras
USB drives, SD cards, CDs, and DVDs do not utilize magnetic technology for data storage and are not affected by magnets. Digital cameras and camcorders are also not prone to damage from magnets.
(Un)Eco-friendly Vehicles and Wind Turbines
When it comes to very popular ECO vehicles nowadays, users of hybrid and electric vehicles should be aware that their cars are built based on high-power neodymium magnets to power the direct current motor usually mounted in the vehicle's wheels. Additionally, wind turbine generators are made of NdFeB magnets producing electrical energy. Besides that, we can find neodymium magnets in office supplies, jewelry, toys, machines, tools, etc. They are simply all around us! But do we really know how to use them properly? Do we really know their capabilities? Do we consider them dangerous?
Fig.1 Neodymium Magnets (source: http://www.unitednuclear.com)
Neodymium magnets are actually made of a neodymium-iron-boron alloy, which allows them to store a tremendous amount of magnetic energy and thus makes them highly resistant to demagnetization (more technical information can be found in the FAQ section). Therefore, NdFeB permanent magnets are considered the strongest magnets in the world! Even a magnet the size of a thumb is difficult to remove from a refrigerator manually. And what happens when two magnets meet? The attractive force between them is so strong that sometimes, when they come close, they collide and break, causing serious damage if something gets in their way...
The best thing to illustrate how dangerous neodymium magnets can be is to insert a photo here that sometimes looks really scary, but since some of you may have weak nerves, I won't include them here and instead send you to check the link added below. In general, you can find many examples on the internet of various injuries to people, such as crushed fingers, broken bones, or perforated intestines, as well as material damages: erasing magnetic storage media [hard drives], erasing information from magnetic stripe credit cards, or permanently distorting color images on old cathode-ray tube televisions. Additionally, neodymium magnets perform well at low temperatures, but when heated, their magnetic field decreases and they become more brittle. If they become overheated, they can even ignite!
Fig.2 Consequences of swallowing neodymium magnets (source: http://www.naspghan.org)
The most common problem when it comes to neodymium magnets is always children. Although magnets are intended for adults, it is very difficult to keep them out of the reach of little people. Shiny, small, and attractive shapes always catch their attention. Based on statistics from the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (http://www.naspghan.org), there are over 200 documented cases of children swallowing these magnets. Most of them required emergency procedures to remove them, but some even required serious surgeries!
- Management of Ingested Magnets in Children. JPGN 2012; 55: 239-243.
- Painful Attraction: A Magnetic Penile Injury. J. R. Soc. Med. 2005; 98 (3); 122-123.