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K&J Online Tools
The Magnet Calculator
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Magnetic Field Calculator
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Magnet Summary Page
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| A K&J exclusive, calculates magnetic pull forces & field strengths for disc, cylinder, block and ring magnets. | Our newest calculator shows the field strength at any point near a disc or cylinder magnet. | Helpful charts make finding our most common magnet sizes easy. | A comprehensive list of available magnet sizes, searchable and sortable. This takes a few seconds to load. |
General Magnet Questions
1. How can I identify the poles of the magnets?Neodymium Magnet Specific
17. What are neodymium magnets? Are they the same as "rare earth"?Magnet Handling
34. How can I separate strong magnets?Platings/Coatings/Adhesives
37. Why are most neodymium magnets plated or coated?Custom/Special Magnets
45. Can you supply custom/special shapes of neodymium magnets?
46. What are the size limitations on manufacturing neodymium magnets?
47. I see you supply plastic- and rubber-coated neodymium magnets. Can I get XXX-size in plastic-coated (or rubber-coated)?
Health, Safety, and Electronics
48. Are there health or safety concerns with neodymium magnets?Special Uses/Applications
55. Can I use neodymium magnets to trigger traffic lights with my motorcycle/moped/bicycle?
56. Which magnets should I use for holding knives to my fridge?
57. Which magnets should I use for holding spice cans to my fridge?
58. I am looking for the equivalent of a magician's M5/PK5 magnet. Which of your magnets is the equivalent?
59. I am making magnetic earrings. Which magnets should I use?
60. I would like to erase hard drives/degauss tapes. Which magnet should I use?
61. Which magnets should I use for magnetic therapy?
62. I would like to use magnets for water treatment. Which magnets should I use?
63. Which magnets should I use for holding pictures and papers to my refrigerator?
64. Which magnets should I use for holding pins/badges through clothing instead of using pins?
65. I heard you can repair dents in brass instruments using magnets. How can I do this?
66. I need magnets for a binder/brochure closure. Which magnets work for this?
Ordering Questions
67. I am trying to order online, but every time I add something to my shopping cart, I get a message that my cart is empty. What do I need to do?
68. I don't want to put my credit card info online. Is there some other way I can pay?
69. Can I get the quantity discount pricing for an odd quantity of magnets (i.e. quantity of 87)?
70. Can I open an account with K&J Magnetics?
71. Can you just put my magnets in a small envelope to save postage?
72. Where can I get a discount code?
Questions about K&J Magnetics
73. Where are you located?
74. Do you have a local distributor near me?
75. Do you have an affiliate program?
76. Do you have a printed catalog?
Misc.
1. How can I identify the poles of the magnets?
There are several simple methods that can be used to identify the (Scientific) North and South poles of neodymium magnets.
1) The easiest way is to use another magnet that is already marked. The North pole of the marked magnet will be attracted to the South pole of the unmarked magnet.
2) If you take an even number of magnets and pinch a string in the middle of the stack and dangle the magnets so they can freely rotate on the string, the North pole of the magnets will eventually settle pointing North. This actually contradicts the "opposites attract" rule of magnetism, but the naming convention of the poles is a carry over from the old days when the poles were called the "North-seeking" and "South-seeking" poles. These were shortened over time to the "North" and "South" poles that we know them as.
3) If you have a compass handy, the end of the needle that
normally points North will be attracted to the South pole of the
neodymium magnet.
4) Use one of our
Pole
Identifier Devices.
(Please note: In some magnetic therapy applications, the definitions of the poles are reversed from the scientific definition described above. Please be sure to confirm the proper definition of the poles prior to using magnets for medical purposes)
Also check out our article, Which Pole is North?
2. Is one pole stronger than the other?
No, both poles are equally strong.
3. Which is the strongest type of magnet?
Neodymium (more precisely Neodymium-Iron-Boron) magnets are the strongest permanent magnets in the world.
4. What does "Magnetized thru thickness" mean?
We use the description "Magnetized thru thickness" to identify the locations of the poles on our block magnets.
The thickness is always the last dimension listed for block
magnets. If you take one of our block magnets and place it
on a flat surface with the thickness dimension as the vertical
dimension, the poles will be on the top and bottom of the magnet
as it sits. For example: Our BX082 blocks are 1" x
1/2" x 1/8" thick. If you place one of the blocks so it is
on a flat surface with 1/8" as the vertical dimension, the poles
will be on the top and bottom as the magnet sits. This
means the poles are located in the middle of the 1" x 1/2" sides.
Click here for
Magnetization Directions Illustrated.
5. What materials do magnets attract?
Ferromagnetic materials are strongly attracted by a magnetic
force. The elements iron (Fe), nickel (Ni), and cobalt
(Co) are the most commonly available elements. Steel is
ferromagnetic because it is an alloy of iron and other metals.
6. What materials can I use to block/shield magnetic fields?
Magnetic fields cannot be blocked, only redirected. The only
materials that will redirect magnetic fields are materials that
are ferromagnetic (attracted to magnets), such as iron, steel
(which contains iron), cobalt, and nickel. The degree of
redirection is proportional to the permeability of the material.
The most efficient shielding material is the 80 Nickel family,
followed by the 50 Nickel family.
7. Can you supply monopole magnets?
No, we don't, nor does anyone else, because they don't exist. All magnets
must have at least two poles.
8. Can you supply a disc/cylinder/ring/sphere magnet with one pole on the outside and one on the inside?
Disc, cylinder, and sphere shapes definitely cannot be
manufactured this way. Rings magnetized this way are
referred to as "radially magnetized", but it is not currently
possible to manufacture neodymium ring magnets this way.
We are working on it, however.
9. Does stacking magnets together make them stronger?
Yes, two or more magnets stacked together will behave exactly like a single magnet of the combined size. For example, if you stacked two of our
D82 disc magnets to form a 1/2" x 1/4" combined size, the two magnets would have the same strength and behave identically to our
D84 discs, which are 1/2" diameter x 1/4" thick.
10. How is the strength of a magnet measured?
Gaussmeters are used to measure the magnetic field density at
the surface of the magnet. This is referred to as the surface
field and is measured in Gauss (or Tesla). Pull Force Testers are used to
test the holding force of a magnet that is in contact with a
flat steel plate. Pull forces are measured in pounds (or kilograms).
11. How is the pull force of each magnet determined?
All of the pull force values we specify have been tested in our laboratory. We test these magnets in two different configurations. Case 1 is the maximum pull force generated between a single magnet and a thick, ground, flat steel plate. Case 2 is the maximum pull force generated with a single magnet sandwiched between two thick, ground, flat steel plates. Case 3 is the maximum pull force generated on a magnet attracted to another magnet of the same type.
The values are an average value for five samples of each magnet. A digital force gauge records the tensile force on the magnet. The plates are pulled apart until the magnet disconnects from one of the plates. The peak value is recorded as the "pull force". If using steel that is thinner, coated, or has an uneven or rusty surface, the effective pull force may be different than recorded in our lab.
12. I am using another online magnet pull force calculator. Why is the pull force
value from the calculator different from K&J Magnetics' pull
force?
Most other online calculators are based on theoretical
formulas, which are notoriously inaccurate, especially for very
large or very small sizes. Our fanatical engineers have worked
long and hard in the laboratory developing our online
calculators that are VERY accurate based on thousands of test
cases. Our pull force
and magnetic field density calculators can be found here:
K&J Magnet
Calculator.
13. Will a magnet with a 20 lb pull force lift a 20 lb object?
Because pull force values are tested under laboratory
conditions, you probably won't achieve the same
holding force under real world conditions. The
effective pull force is reduced by uneven
contact with the metal surface, pulling in a
direction that is not perpendicular to the
steel, attaching to metal that is thinner than
ideal, surface coatings, and other factors.
14. Can you supply BH Curves, or Demagnetization Curves for your magnets?
Yes, we've posted Demagnetization Curves for our most common Neodymium magnet grades right here.
15. What does a magnetic field look like?
The traditional way of visualizing magnetic fields is to place a magnet near a surface covered with iron filings. If you already have some of our magnets, this is a good experiment to conduct! In the meantime, we've created a series of images using Finite Element Analysis software, which can be viewed here.
16. How do magnets really work?
This is a very interesting question. It's actually a difficult question to answer well. As the late, great physicist Richard Feynman once said, "How much of an explanation is enough to satisfy you?" To watch him describe the difficulty in answering this question, check out Feynman: How do Magnets Work on YouTube.
If you do want more details, this interesting video: How Special Relativity Makes Magnets Work has a great description about why an electromagnet is attracted to iron.
Their follow-on video, MAGNETS: How Do They Work? is even more relevant to permanent magnets. It addresses how permanent magnets with (seemingly) no current running through them can act magnetic. Ironically, even with that incredible level of detail, at some point they still end up saying, "(Why?) No one knows. We just know that's the way the universe works." Feynman was a pretty smart guy!
17. What are neodymium magnets? Are they the same as "rare earth"?
Neodymium magnets are a member of the rare earth magnet family. They are called "rare earth" because neodymium is a member of the "rare earth" elements on the periodic table. Neodymium magnets are the strongest of the rare earth magnets and are the strongest permanent magnets in the world.
18. What are neodymium magnets made from and
how are they made?
Neodymium magnets are actually composed of neodymium, iron
and boron (they are also referred to as NIB or NdFeB magnets).
The powdered mixture is pressed under great pressure into
molds. The material is then sintered (heated under a
vacuum), cooled, and then ground or sliced into
the desired shape. Coatings are then applied if
required.
Finally, the blank magnets are magnetized by exposing them
to a very powerful magnetic field in excess of 30 KOe.
19. What does the "N rating", or grade, of the neodymium magnets mean?
The grade, or "N rating" of the magnet refers to the Maximum
Energy Product of the material that the magnet is made from.
It refers to the maximum strength that the material can be
magnetized to. The grade of neodymium magnets is
generally measured in units millions of Gauss Oersted (MGOe).
A magnet of grade N42 has a Maximum Energy Product of 42 MGOe. Generally speaking, the higher the grade, the
stronger the magnet.
20. Can I cut, drill, or machine neodymium magnets?
The Neodymium Iron Boron material is very hard and brittle,
so machining is difficult at best. The hardness of the
material is RC46 on the Rockwell "C" scale, which is harder than
commercially available drills and tooling, so these tools will
heat up and become damaged if used on NdFeB material. Diamond tooling, EDM (Electrostatic Discharge
Machines), and abrasives are the preferred methods for shaping
neodymium magnet material. Machining of neodymium magnets should
only be done by experienced machinists familiar with the risk
and safety issues involved. The heat generated during machining
can demagnetize the magnet and could cause it to
catch fire posing a safety risk. The dry powder
produced while machining is also very flammable and great care
must be taken to avoid combustion of this material.
21. Can I solder or weld to neodymium magnets?
You definitely cannot solder or weld to neodymium magnets. The
heat will demagnetize the magnet and could cause it to catch
fire posing a safety risk.
22. Do I have to worry about temperature with neodymium
magnets?
Yes. Neodymium Iron Boron magnets are sensitive to
heat. If a magnet heated above its maximum operating
temperature (176°F (80°C) for standard N grades) the magnet
will permanently lose a fraction of its magnetic strength.
If they are heated above their Curie temperature (590°F (310°C)
for standard N grades), they will lose all of their magnetic
properties. Different grades of neodymium different
maximum operating and Curie temperatures. See our
Neodymium Magnet Specifications Page
for more details. We do stock a range of
high
temperature magnets, which you can see
here.
23. What is the gauss rating of your magnets?
This depends on the context it is used. Most magnetic therapy
people like to present the largest number possible, so they
often use the
Residual
Flux Density (Brmax) of the material, which
really doesn't specify much about the actual magnet. This value
is essentially the magnetic field density inside the
magnet material. Since you will never be inside the
magnet, or using the field inside the magnet, this value doesn't
really have any practical value. The
surface field of a magnet is a much more accurate
specification for a magnet. The surface field is exactly
what it sounds like. It is the magnetic field density at the
surface of the magnet as measured by a Gaussmeter. This value is
tested and specified for each of our stock magnets. A
comprehensive table of the surface field density for each of our
stock magnets can be seen here:
Magnet Summary Table.
24. Do neodymium magnets require a keeper?
No, neodymium magnets do not require a keeper for storage
like Alnico magnets.
25. Will my neodymium magnets lose strength over time?
Very little. Neodymium magnets are the strongest and most
permanent magnets known to man. If they are not overheated
or physically damaged, neodymium magnets will lose less than 1% of their strength over 10 years - not enough for you to notice unless you have very sensitive measuring equipment.
They won't even lose their strength if they are held in
repelling or attracting positions with other magnets over long
periods of time.
26. Will neodymium magnets lose strength if they are held in repelling or attracting positions for a long time?
In most applications, the answer is simply "no". If the magnets
will be exposed to higher temperatures while in repelling
applications, the answer is "possibly". The exact answer is a
bit too complicated for a FAQ answer, and requires specifics
about the application.
27. What are neodymium magnets used for?
Just about anything you can imagine! Please see our
Uses Page for a list of some of the
applications for these incredible magnets.
28. How is neodymium pronounced?
From a dictionary: [nē ō dim ē um]. Or, nee-oh-dim-ee-um.
The only real trick to pronouncing it correctly is to treat the
'y' as an 'i'. It is pronounced as if it were spelled "neodimium".
29. Are your Neodymium Rare Earth Magnets RoHS compliant?
Yes, our magnets are fully RoHS compliant, meeting the European Parliament Directive entitled "Restrictions on the use Of Hazardous Substances" (RoHS). This Directive prohibits the use of the following elements in electrical/electronic equipment sold after 7/1/2006: cadmium (Cd), lead (Pb), mercury (Hg), hexavalent chromium (Cr(VI)), polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs). Download an official RoHS Compliance Statement from K&J Magnetics here. Or, you can find individual PDF files for each specific magnet on the product detail pages, under the "Downloads" tab.
30. Can I make a magnet that I already have any stronger?
No, once a magnet is fully magnetized (saturated), it cannot be made any stronger.
31. I need a magnet the size of a penny/nickel/dime/quarter. What size do I need?
Here are the dimensions of these coins along with the
closest matching magnet that we currently stock:
32. What is the difference between the maximum operating temperature and the Curie temperature of the magnets?
The maximum operating temperature is the maximum temperature the magnet may be continuously
subjected to with no significant loss of magnetic strength. This
is 176ºF (80ºC) for standard grades of neodymium magnets. The
Curie Temperature is the temperature at which the magnet will become completely demagnetized.
This is 590ºF (310ºC) for standard grades of neodymium magnets.
Higher temperature grades have higher maximum operating
temperatures and higher Curie Temperatures. At temperatures
between these two points, a magnet will permanently lose a
portion of its magnetic strength. The loss will be greater the
closer to the Curie Temperature it is heated.
For a more in-depth explanation, check out our article: Temperature and Neodymium Magnets.
33. How strong of a magnetic field is necessary to magnetize a neodymium magnet?
As a general rule of thumb, a peak field of between 2 and
2.5 times the intrinsic coercivity is required to fully
saturate a magnet. For standard neodymium magnets, the field
required is minimum of 24 KOe, but 30 KOe is usually the
minimum used.
34. How do I separate large magnets?
Small and medium-sized magnets can usually be separated by hand by sliding the end magnet off of the stack. Medium-large magnets can
often be separated by using the edge of a table or countertop. Place the magnets a table top with one of the magnets hanging over the edge. Then, using your body weight, hold the magnet(s) on the table and push down on the magnet hanging over the edge. With a little work and practice, you should be able to slide the magnets apart. Just be careful that they don't snap back together once they become separated. For very large magnets (generally 2" and
larger), we use a specially made magnet separating tool. You can see pictures of one of these tools as well as instructions on how to build your own on this page: Build your own magnet separating tool.
For a more in-depth explanation, check out our article: How to Separate Strong Magnets, which includes a number of short videos.
35. I have metal dust all over my magnets. How can I remove it?
Using adhesive tape to capture the metal dust is the best way to
clean magnets.
36. Are there any regulations for shipping magnets?
According to the United States Department of Transportation and the Office of Hazardous Materials Safety,
the limit for shipping magnets by air is a magnetic field
strength of 0.00525 Gauss measured at 15 feet (4.5 meters) from
any point on the outside of the package. There are no
restrictions on the shipping of magnetized materials by ground. When in doubt, ship magnets by ground transportation.
For a more in-depth explanation, check out our article about Shipping Magnets.
37. Why are most neodymium magnets plated
or coated?
Neodymium magnets are composed mainly of Neodymium, Iron, and
Boron. If neodymium magnets are not plated, the iron in the
material will oxidize very easily if exposed to moisture. Even
normal humidity will rust the iron over time. To protect the
iron from exposure to moisture, most neodymium magnets are
plated or coated.
38. What is the difference between the different platings and coatings?
Choosing different coatings does not affect the magnetic strength or performance of the magnet, except for our Plastic and Rubber Coated Magnets. The preferred coating is dictated by preference or intended application. More detailed specifications can be found on our Specs page.
39. Can I paint over the nickel plating?
Yes, you can use any paint formulated for use on metal surfaces. Spray-on paint seems to work best. Roughing the surface first can help improve paint adhesion to the smooth, nickel plated surface. Sandblasting or beadblasting works, as well as an etching primer.
40. What is the thickness of the nickel (Ni-Cu-Ni) plating?
The nickel plating is actually triple plating of nickel-copper-nickel.
The layers are Ni: 5-6µm,
Cu: 7-8µm,
Ni: 5-6µm, for a total thickness of 17-20µm.
41. Do you stock any unplated magnets?
As mentioned above, the iron in the NdFeB material will
oxidize if it is exposed to moisture. For this reason, we do not
stock any unplated magnets. We can supply unplated magnets as
custom order
items.
42. What is the best adhesive to use with your magnets?
We and several customers have had great success adhering to the nickel-plating using Loctite 39205 (an acrylic adhesive) with Loctite 7380 activator. A Loctite representative also recommended Loctite 3032 (a 2-part acrylic adhesive) with Loctite primer 770. For more commonly found adhesives, we have also had great results using many kinds of epoxy, often sold as "5-minute" epoxy. "Liquid Nails" and "Gorilla Glue" can also work well, and are available in most hardware and home supply stores. It does help to scratch the surface of the plating lightly with sandpaper or other abrasive prior to applying the adhesive. For more information, read our in-depth article: Sticky Business: How to Glue Neodymium Magnets.
43. I noticed that the plastic- and rubber-coated magnets have a lower pull force than nickel-plated magnets of the same size. Does the plastic/rubber weaken the magnet?
These materials don't "weaken" the magnet, but the volume of
magnet material is reduced to allow room for the coatings, which
reduces the pull force. The layer of plastic or rubber also
creates distance between the magnet and metal surface which also
reduces the pull force.
44. How can I protect my magnets from damage due to impact?
We have found that wrapping magnets with a few layers of
electrical tape protects them from most damage caused by
collisions with other magnets and hard surfaces. Another
great way to protect your magnets from damage and the elements
is to coat them with
rubberized
coating. We have created a page with
step-by-step
instructions on how to do this. We also stock
several sizes and shapes of
plastic-coated and rubber-coated magnets.
45. I need a special size/shape of neodymium
magnet. Can you supply custom magnets?
Yes, we can supply custom magnets. You can find details on
our Custom
Magnet Page.
46. What are the size limitations on manufacturing neodymium magnets?
The limits include:
2" max in magnetized direction
4" max diameter for discs and rings
4" max length and width for blocks
1/32" minimum on thickness on any magnet
1/16" minimum diameter on outer diameter
1/16" minimum diameter on any hole
47. I see you supply plastic- and rubber-coated neodymium magnets. Can I get XXX-size in plastic-coated (or rubber-coated)?
Maybe. Each size of plastic- and rubber-coated magnet
requires its own special mold. These molds cost anywhere from
$300-$2500, depending on the size and shape. If you are in need
of a large quantity, creating a new mold may be worthwhile. If
you only need a few, then
doing your
own rubber-coating may be a more cost-effective solution.
48. Are there health or safety concerns with neo magnets?
There are no known health
concerns with exposure to permanent magnetic fields. In fact, many people believe that magnets can
be used to speed up the healing process. There may be issues
with people with pacemakers or other implanted medical devices handling or being around strong
magnets. We are not medical professionals, so we cannot offer complete
guidance on pacemaker safety. We've shared what we do know in our article about Pacemaker Safety. Please consult a physician for
this information. There are
several safety concerns when handling strong magnets.
Please refer to our Safety Page
for complete details.
49. What is a safe distance to keep magnets away from pacemakers?
We are not medical professionals, so we cannot offer complete guidance on
pacemaker safety, or about any specific medical device. Please consult a physician and/or the manufacturer of your device for this
information. We've shared what we do know in our article about Pacemaker Safety.
50. Will magnets harm my electronics?
Maybe...The strong magnetic fields of these magnets can damage certain magnetic media such as floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes or other such devices. They can also damage televisions, VCRs, computer monitors and other CRT displays. Never place neodymium magnets near any of these appliances.
As for other electronics such as cell phones, iPods,
flash drives, calculators and similar devices that do not contain
magnetic storage media, probably not, but it is best to err
on the safe side and try to avoid close contact between neo
magnets and electronics.
51. How far away from electronics should I keep my magnets?
This depends on a lot of factors, but as a general rule of
thumb, we recommend keeping the distance between magnets and
electronics 4" + 1" for every 10 lbs of pull force.
52. Will using magnets on my refrigerator, stove, oven, or microwave harm the appliance?
No, magnets will not harm any of these appliances.
53. Will magnets erase my hard drive or harm my
computer?
Not unless you really work at it. While you probably don't want to stick magnets
directly to your computer case, having them nearby will not harm
your computer. Magnets can damage floppy disks and
magnetic tape storage media, so you must keep magnets away from
these items. They should not, however, damage any data on
your hard drive unless you place a very large and powerful
magnet directly on top of the drive. Every hard drive already contains a
powerful neodymium magnet, so one moving around outside the case
will not affect the data. Here is an article from PCWorld
Magazine to support this:
http://msn.pcworld.com/article/id,116572-page,1/article.html.
We tried scrambling the contents of a running hard drive ourselves, and documented our failure to erase all the data in our article, Hard Drive Destruction
54. I am developing a product using magnets. Do I have to put a
safety warning on it about pacemakers/electronics?
While we love answering technical questions about magnets, this one sounds more like a legal question. We're definitely not qualified to provide legal advice.
Again, we are not medical professionals, so we cannot provide firm details on pacemaker issues. As for safety and electronics, it really depends on the application of your product, the size of the magnet(s), how the magnet is used, and where the magnet is located within the product. We recommend providing any warnings that you think may be an issue.
55. Can I use neodymium magnets to trigger traffic lights with my motorcycle/moped/bicycle?
This one is a definite "maybe". We have received feedback that
magnets as small as our
D84
discs have successfully triggered traffic lights, but we
have also received reports that magnets as large as our
DX8C
have failed to trip similar traffic light sensors. It seems that
there are different types and different sensitivities of traffic
light sensors, and magnets will trigger some, but not all of
them. If you have any feedback or good information on this, we
would appreciate an
email with any details you may have.
56. Which magnets should I use for holding knives to my fridge?
For small knives, small magnets like our
B444 cubes are sufficient. For butcher knives and other large knives, we recommend our
BX084 blocks.
Mid-sized knives can be held to a refrigerator using our
B884 blocks.
Also check out our Magnetic Knife Holder article, which describes how to build a magnetic knife block!
57. Which magnets should I use for holding spice cans to my fridge?
The answer varies depending on the size of the can and the
weight of the items being stored. Magnets as small as our
D81 discs can be used to hold smaller cans, while magnets
as large as our
DC2
dics may be required to hold very large cans.
58. I am looking for the equivalent of a magician's M5/PK5 magnet. Which of your magnets is the equivalent?
The magician's M5 (aka PK5) magnet is the equivalent of our
BY0Y08 block magnet.
59. I am making magnetic earrings. Which magnets should I use?
The best size varies, depending on the size of the decorations
being held. Generally, the best options are discs like our
D31-N52 or
D41-N52. Other magnets of similar size can also be used.
60. I would like to erase hard drives/degauss tapes. Which magnet should I use?
Magnetic tapes can be erased with a strong magnet. Popular choices include: DX8C, DY0X0, or BY0Y08.
We used to think that a sufficiently large magnet would scramble the data on a hard drive. Some recent experiments we have conducted seem to disagree. See our blog article on the subject for more details. We don't recommend this method if you must be sure that the data is gone -- physical destruction of the drive is the safest choice.
61. Which magnets should I use for magnetic therapy?
A wide range of sizes can be used for magnetic therapy. Many
people use magnets as small as our
D41
discs for spot treatment, while others use magnets as large
as our
DY04 discs for large area
treatment. It is best to select a size that "fits" the area being treated.
62. I would like to use magnets for water treatment. Which magnets should I use?
Magnets on the main water line should be of dimensions 1.5 - 2.5 times the outside
diameter of the pipe coming in. Larger magnets will provide a stronger and more consistent magnetic field between them. For this application, we often recommend our
BY0Y08
blocks. They will work well on any water line up to 1.5" in diameter.
Water conditioning works best if you use two magnets, one on each side of the pipe in attracting arrangement. The two magnets in this arrangement create the strongest possible magnetic field between them. It works very well if you have two "shims" which are the same thickness as the diameter of the water pipe. If you tape the shims to either side of the pipe, they will provide a flat surface for the magnets to
rest on. The large magnets should hold each other in place across the pipe and shims.
The magnets can then be held in place with tape to prevent them from slipping off
due to vibration.
Interested in learning more about how magnetic water treatment might work? Check out our Magnetic Water Treatment article, where we discover some surprising facts about this controversial subject!
63. Which magnets should I use for holding pictures and papers to my refrigerator?
For refrigerator magnets, there are many options. We carry a
neat line of
magnetic thumbtacks as well as dozens of other shapes and
sizes that work well. A few suggestions are our
D42,
D34,
B333,
S4
(also available in black color or gold), and
ST4
stars. Many other magnets of similar sizes will also work
very well for fridge magnets.
Also check out our Refrigerator Magnets section, which includes a number of great suggested magnets.
64. Which magnets should I use for holding pins/badges through clothing instead of using pins?
For holding average-sized pins and badges, we recommend our
D62
disc magnets, as they provide the appropriate amount of pull
strength through a wide range of fabric thicknesses. If you will
be holding large or heavy pins or badges, or will be holding
through exceptionally thick material, then our
D72
or
D82 discs may be necessary to provide enough holding force.
Also check out our Sewing Magnets that are made specifically for use as magnetic closures. They are intended to be sewn inside the fabric, remaining hidden from view.
They come in 3 different sizes and are sold in matched pairs. Also note that some have a thin plastic cover that protects them from moisture, which is an excellent solution for anything that goes through the washing machine.
See our Sewing Magnet Article for an example of how to use them. There, we describe how we replaced the Velcro fasteners on a pair of cargo shorts.
65. I heard you can repair dents in brass instruments using magnets. How can I do this?
Dent removal is accomplished by inserting a steel ball into the
instrument as close to, but smaller than, the diameter of the
section of tubing being repaired. The steel ball can be moved
through the tube using a magnet on the outside. Working the
steel ball over the damaged area will gradually smooth out the
dent. A magnet like our
DX0X0 will pull out most small- and medium-sized dents,
while a larger magnet like our
DX8C may be necessary for larger and more stubborn dents. We
do carry a line of
steel
balls that can be used for this application.
66. I need magnets for a binder/brochure closure. Which magnets work for this?
We have many printers and other customers that use our magnets
in brochures and binders to hold them closed. The most common
sizes used for brochures and binders are our
D401,
D41,
D501,
D51,
D601,
D61,
D701,
D71,
D801,
D81
disc magnets, and our
B4401,
B441,
B6301,
B631,
B661,
B821,
B841,
B8801, and
B881 block magnets, but larger sizes can also be used for larger applications.
See our Adhesive Backed Magnets article for a great example of how to do this.
67. I am trying to order online, but every
time I add something to my shopping cart, I get a message
that my cart is empty. What do I need to do?
Most of the time, this is caused by cookies being disabled
on your computer. Our shopping cart must be allowed to
write a small cookie to your computer to "remember" what you
place in your shopping cart. To find out how to enable
cookies for various browsers, please refer to this web page: Google: How
to Enable Cookies. If you continue to have
difficulty ordering online, you can order by phone by
calling us at 215-766-8055 during normal business hours.
68. I don't want to put my credit card info online. Is there some other way I can pay?
We take every measure possible to ensure that your online
transaction with us is secure. You can read more about
this on our
Security
Page. If you would still prefer not to order
online, there are many other ways to place an order with us.
Please see our Ordering/Shipping
Page for more details.
69. Can I get the quantity discount pricing for an odd quantity of magnets (i.e. quantity of 87)?
Yes. If you are ordering an odd quantity of a particular
magnet, you can get the quantity pricing by simply adding a
single magnet to your shopping cart. Then, while viewing the
shopping cart, change the quantity from "1" to your desired
quantity and click "Update Totals". The shopping cart will
recalculate the price and total and will give you the quantity
discounted price.
70. Can I open an account with K&J Magnetics?
Yes. We accept Purchase Orders from businesses with approved credit. To apply for credit, email your credit information to us at contactus@kjmagnetics.com. Please be sure to include a point of contact in both your Purchasing and Accounts Payable departments, including their email addresses, mailing addresses, fax, and phone numbers. Account setup takes approximately 7 - 10 business days from receipt of all requested information. Terms of all Purchase Orders are Net 30. There is a $50 minimum for orders placed by Purchase Order (not including shipping). All POs are shipped via UPS or FedEx. Purchase Orders must be received via email as a .jpg or .pdf attachment. Verbal Purchase Orders will not be accepted.
71. Can you just put my magnets in a small envelope to save postage?
No.
All magnets must be shipped in a box in order to comply with
United States Department of Transportation, USPS, UPS, and FedEx regulations
for the shipment of magnetic materials.
72. Where can I get a discount code?
You can receive discounts by joining our
Mailing List. Our periodic newsletter (sent once every
month or two) contains news, new products and Mailing List-only
coupons and specials!
73. Where are you located?
Our main offices and warehouse is currently located in Pipersville, PA, about 30 miles north of Philadelphia. We currently do not have a retail store, nor do we accept walk-in customers or pick-ups at this time.
74. Do you have a local distributor near me?
We do not have any local distributors of our magnets. All sales are through our website
www.kjmagnetics.com.
75. Do you have an affiliate program?
Yes, we do. If you have a website and would like to earn
commissions for sales generated by your link to our store,
please email us for details.
76. Do you have a printed catalog?
No we do not have a printed catalog available. Find information about all of our magnets online, here at our website.
77. Are neodymium magnets affected by recent changes in US Conflict Minerals Law, as made in section 1502 of the Dodd-Frank Wall Street Reform and Consumer Protection Act?
This law requires reporting of the use of columbite-tantalite (tantalum, used in capacitors), cassiterite (used to make tin), wolframite (tungsten) and gold that comes from mines located in the eastern part of the Democratic Reublic of Congo. Since neodymium magnets don't usually contain these elements, they shouldn't be covered by this law. Learn more about what elements are used in the manufacture of neodymium magnets in our article: How Neodymium Magnets are Made.
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