Buying guide for best neodymium magnets
If you’ve ever lost paperwork because your refrigerator magnet slipped, you obviously weren’t using a neodymium magnet. If you’re tired of getting assaulted by appointment notices and kindergarten artwork every time you look for a snack, maybe it’s time to make the switch.
Neodymium (Nd) magnets were developed in the 1980s for industrial use by researchers in the auto and steel industries. These rare earth magnets are still used today in a wide variety of products, such as door locks, headphones, and motors. Today, these extra-strong magnets have also made their way into household, crafting, and jewelry applications, too.
Rare earth magnets are made from a mixture of 17 rare earth metals — metals that are uncommon to find in large, usable amounts. Neodymium magnets are the most affordable and strongest of these magnets. Their extreme strength does present some special challenges, so it’s important to think about your project before getting them.
Key considerations
Strength
Some manufacturers use well-protected neodymium magnets in toys, but these powerful rare earth magnets aren’t playthings. Even coin-size magnets have enough attractive force to pinch fingers if used carelessly.
Neodymium magnets are usually categorized by the power of their magnetic field (measured in gauss or tesla). Grades range from N35 (weakest) to N52 (strongest). The amount of weight each magnet can hold depends on its size and thickness, but an N52 magnet contains about 50% more pull force (the amount of force, in pounds, it takes to move the magnet away from something) than an N35 magnet. Most neodymium magnets on the consumer market are graded between N40 and N42. Even small 8-millimeter disc magnets in this consumer range can easily hold laminated sheets or paper stacks of five or more sheets. Magnets ranging from the size of a penny to a quarter can pull with 15 to 30 pounds of force, depending upon their rating.
Shape
You’ll usually find rare earth magnets shaped into discs, bars, and squares. If you need a significant amount of pull force, cubes are your best bet. Because of their thickness and density, they pack more power into a small footprint. For most applications, shape is a matter of preference, although different shapes lend themselves better to certain applications:
Bar: These magnets often perform better for projects where length is key, like knife holders, tool holders, or for hanging baking pans on a refrigerator or metal cabinet.
Rectangle: This shape more easily lines up with drawer and cabinet corners.
Round: These magnets work best for jewelry and most crafts since they take up less surface area and lack corners that will break if dropped.
Care and safety
Neodymium magnets have endless uses, but not every magnet is a good fit for every use.
A favorite among crafters, neodymium magnets are used for everything from refrigerator décor to jewelry and bookmarks. But, according to the Centers for Disease Control, crafters under the age of six shouldn’t use these magnets. Swallowing a single magnet poses a choking hazard; swallowing a pair of magnets or a magnet and metal object can create a potentially deadly bowel constriction or blockage. This danger is especially serious with neodymium magnets since they’re more than ten times stronger than ceramic magnets of a similar size.
Neodymium magnets also should not be used in projects where they are subjected to significant force. Rare earth magnets are very brittle and can break if they’re dropped on hard surfaces. Edges can also shatter if two magnets — or a magnet and a metal object — collide with too much force. This is a real possibility, given their strength.
Neodymium magnets do not naturally resist corrosion, so they aren’t a good choice for outdoor projects where they’re vulnerable to precipitation, or indoor applications where they could be exposed to water. Some magnets are coated to resist water, but the coatings are not always effective or long-lasting.
Sintered vs. bonded
Neodymium magnets are made either by sintering or bonding. Both processes produce magnets that are strong enough for consumer use.
Sintered: When magnets are sintered, their metal components are melted together, cooled, ground down to a powder, and pressed into shape. An exterior molding helps them retain that shape. Sintered magnets can be crafted to have higher magnetic concentrations in specific areas, which makes them helpful in industrial applications.
Bonded: Bonded magnets feature magnetic strips of material injected into polymer or resin molds. Bonded magnets do not have as much magnetic force as sintered magnets, but they stand up better to bangs and drops.
Features
Neodymium magnets are extremely useful, but they have a few challenging drawbacks. Several features can help make them more practical.
Attachments
Thanks to their brittle texture, rare earth magnets can’t be drilled aftermarket, but some manufacturers mold neodymium magnets to have one or more openings that can accommodate a screw or string. When screwing your magnet into a nonmagnetic surface, take care not to overtighten it, since it can also crack the neodymium. Also, keep in mind that openings diminish the magnet’s density and surface area, thus reducing its magnetic force. For this reason, some neodymium magnets come with an adhesive backing to attach to nonmagnetic surfaces without holes and screws.
Coatings
Most neodymium magnets are coated for a number of reasons. The coating helps to protect the brittle material from chipping or cracking if too much force is applied to it. A coating can also help prevent corrosion, which can occur in high humidity, thanks to the magnets’ iron content. Coated magnets are less likely to scratch refrigerators, whiteboards, and other magnetic surfaces. Most neodymium magnets are coated with layers of copper and nickel, but some have less common coatings, such as nonstick, for specific applications.
Storage
Careful shipping and storage are important with neodymium magnets. Bulk sets shipped without padding or a separating buffer between each magnet are more prone to breaking. The magnets can be difficult to separate, too. Larger magnets must be properly packaged to avoid attracting other nearby items, and the packaging may be your best option for magnet storage as well. To avoid damage in transit, the best neodymium magnets are packaged in containers that isolate their magnetic force.
Accessories
Flexible magnets: Craftopia Magnetic Adhesive Sheets
If neodymium magnets aren’t quite what you need for crafting, consider this pack of ten adhesive sheets. They can be cut to virtually any size and shape and are safer for little hands to use. And the adhesive backing lets you skip messy steps involving glue, so your project sticks where you want it to and nowhere you don’t.
Neodymium magnet prices
Neodymium magnets cost anywhere from a few cents each for small magnets found in bulk to several dollars for one large magnet. The number on the price tag increases with the pull force, so it’s important to think about how much force you really need.
Inexpensive: The least expensive neodymium magnets cost less than $0.10 per magnet when bought in bulk packs of 50 to more than 100. Most of these are small and round, measuring about 1/3 inch in diameter. They have more pulling power than standard magnets but less than larger magnets.
Mid-range: The middle tier of neodymium magnets is wide, ranging from about $1.25 to $1.75 per magnet. These are still sold in bulk, with roughly 5 to 10 magnets per pack. You’ll find magnets that are both round, slightly larger than a penny, and rectangular, measuring more than 2 inches long. Most have 15 to 30 pounds of pull force.
Expensive: The most expensive neodymium magnets cost $5 or more per magnet, depending on the grade and strength. You can get large neodymium magnets with anywhere from 100 to 600 pounds of pull force, generally paying $0.05 to $0.09 cents per pound of force. Magnets in this price range exert a serious force that can be hard to control, so it’s recommended that you use them only for specific purposes.
Tips
- Work on a metal table. Having trouble getting your magnets to stay in place? Trying working on a metal table or other magnetic surface, so the magnets stay put rather than stick together.
- Try a magnet instead of a stud finder. Need to find a wall stud? If you don’t have a stud finder, a neodymium magnet can serve as a stand-in.
- Keep the magnets apart. Always keep neodymium magnets separated so they won’t jump and slam into one another or into fingers when you’re handling them. Smaller, coin-size magnets should be kept at least 4 inches apart. Cubes of 1 inch may need at least 2 feet of distance to remain safe.
FAQ
Q. How do you separate neodymium magnets?
A: It’s hard to exert enough force on two neodymium magnets to pull them apart, especially if you’re working with an extremely small surface area. Rather than separating them directly, it’s easiest to quickly slide one off the side. If you’re ordering a whole stack, keep the stack together so you have a larger surface to grip, and slide the magnets off individually when it’s time to use them.
Q. Why shouldn’t I use neodymium magnets in projects that involve drilling?
A. There are several reasons. First, neodymium magnets are extremely brittle and may not tolerate the drilling without breaking. And even if they do, it’s possible that the high heat from the drill bit will demagnetize the magnet. Finally, if the magnet survives the drilling intact and maintains its magnetic force, it may be open to corrosion at the drilling site. If your household or craft project requires an opening, look for neodymium magnets that have been manufactured with an opening.
Q. What can I do with the extra magnets in my bulk pack?
A. You can store them — carefully — for later use, or you can make use of them now! Many customers find plenty of creative uses for their “extra” magnets. Use them to keep a bed skirt in place on a metal bed frame or sheer curtains hanging straight against a metal window frame. Few people complain about having too many refrigerator or whiteboard magnets. Strengthen your cabinet closures or better organize your office supplies. The possibilities are endless.
