Q:How rugged are the
Rare Earth magnets are extremely
brittle and are vulnerable to corrosion. If you let them slam together
they can shatter, crack or chip.
Q:Will my magnets
demagnetize if I heat them?
Yes, if you heat them beyond 170
degrees Fahrenheit (80 degrees Celsius) the magnets will quickly loose
their magnetic properties. Sustaining these temperatures for a length
of time or heating the magnet significantly higher than this will
permanently demagnetize it. Other types of magnets such as
Samarium-Cobalt have higher heat resistance(below 300 degree
Celsius). There are also other types of Nd-Fe-B magnets that are
not as susceptible to heat induced flux degradation,H grade could
withstand 100 degree Celsius,SH grade 150 oC ,UH grade 180oC,and EH
Q:I would like to get a
single pole magnet?
They don’t exist. All
magnets have two poles,N and S.
Q:Do magnets pose a
No, unless you have an internal
medical device such as a pacemaker that would be affected by a strong
magnetic field. However, Nd-Fe-B magnets are very strong and
should be handled with care. These magnets can pinch if allowed to
come together against the skin. Keep away from children, swallowing
more then one can cause problems if they come together in the intesinal
Q:How thick could the
plating thickness of NdFeb be?
Present technology could only
plate Ndfeb magnet with max.30 microns thickness. as the plating will
bubble and come off if it surpass 30 microns.
Q:How are your magnets
measured and graded for strength, quality, etc.?
Magnet Strength Measurements (B)
--The units for measuring the field strength (flux density) of a magnet
are Gauss or Tesla. 1 Tesla = 10,000 Gauss.There are different ways to
classify and measure field strength:
B (flux density): This is the
measurement (in Gauss or Tesla) you get when you use a gaussmeter at
the surface of a magnet. The reading is completely dependant on the
distance from the surface, the shape of the magnet, the exact location
measured, the thickness of the probe and of the magnet's plating. Steel
behind a magnet will increase the measured 'B' significantly. Not a
very good way to compare magnets, since B varies so much depending on
Br (residual flux density): The
maximum flux a magnet can produce, measured only in a closed magnetic
circuit.They are a good way to compare magnet strength...
B-H Curve: Also called a
"hysteresis loop," this graph shows how a magnetic material performs as
it is brought to saturation, demagnetized, saturated in the opposite
direction, then demagnetized again by an external field. The second
quadrant of the graph is the most important in actual use--the point
where the curve crosses the B axis is Br, and the point where it
crosses the H axis is Hc (see below). The product of Br and Hc is
BHmax.very complicated and expensive equipment is needed to plot a B-H
Magnet Quality (BHmax): The
quality of magnetic materials is best stated by the Maximum Energy
Product (BHmax), measured in MegaGauss Oersted (MGOe). This is because
the size and shape of a magnet and the material behind it (such as
iron) have a large effect on the measured field strength at the
surface, as does the exact location at which it measured.
Coercivity (Hc): This measures a
magnet's resistance to demagnetization. It is the external magnetic
field strength required to magnetize, de-magnetize or re-magnetize a
material, also measured in Gauss or Tesla.
Q:Will magnets corrode
if used outdoors?
NdFeB magnets are susceptible to corrosion. The 'Fe' in the name stands
for Iron, and it rusts easily as it’s atom is quite active and
it’s easily oxidated! Many of our magnets come with a Nickel,
Zinc, Gold or Epoxy coating to protect them from moisture. If the
coating is damaged ， the magnet could rust if exposed to water or
Q:How are magnets
manufactured? Can I make them at home?
Manufacturing: NdFeB magnets are complicated to manufacture. The raw
material should be firstly made into alloy, powdered, orientated in
magnetic field, shaped, finally sintered. All of the process should be
done with the protection of nitrogen. After sintered process, the
finished raw magnets should be inspected in terms of magnetic
properties, then finally machined to the sizes required and plated with
surface coating. To magnetize them, they are placed in a very expensive
machine that generates an extremely high-powered magnetic field for an
instant, using high-voltage capacitor discharge and coils. The polarity
of the finished magnet depends on how it was oriented in the
magnetizing machine, and how the particles in the sintered mixture were
oriented. So that makes home manufacture impossible. You CAN, however,
make a simple steel magnet at home. Take a nail and stroke it with a
strong NdFeB magnet 20 or 30 times, ALWAYS moving the magnet in only
one direction on the nail. Presto, the nail will be magnetized,
although very weakly and it’ll demagnetize shortly.
Q:How can you ship
magnets safely? Don't they affect airplane safety?
We take great care when packing
orders to see that any magnetic fields are well contained within the
box(wooden box or carton) we send them in. We pack very carefully so
the external magnetic fields cancel out, and we use steel box liners as
needed to insure that every box is safe and non-magnetic to comply with
national and international postal regulations. We also test each
package before it goes out to be sure it complies with all regulations
Q:How about the
application of Ndfeb magnets?
Permanent Motor, Linear Motors,
Mini motor(libration motor), Motors for electric bicycle, Speakers,
Telecommunication, Computer drive,VCD,DVD, CD-ROM, OA equipment, Home
appliance, Meters, Magnetic separator(used in Food, Mine, Glass and
Coal industry),Magnetic cranes, Magnetic salvage and Magnetic chucks,
Magnetic jewelry, Toys, Button, Magnetic therapy, Nuclear magnetism
resonance, Magnetic health care, Stop motion animation, Diamagnetic
leviation, Electrodynamic bearings, Launched roller coasters, LED
throwies, Guitar pickups.
and on the lighter side
Cow magnets are popular with
dairy farmers and veterinarians to help prevent Hardware Disease in
their cattle. While grazing, cows eat everything from grass and dirt to
nails, staples and bits of bailing wire (referred to as tramp iron).
Tramp iron tends to lodge in the honeycombed walls of the recticulum,
threatening the surrounding vital organs and causing irritation and
inflammation, known as Hardware Disease. The cow loses her appetite and
decreases her milk output (dairy cows), or her ability to gain weight
(feeder stock). Cow magnets help prevent this disease by attracting
stray metal from the folds and crevices of the rumen and recticulum.
One magnet works for the life of the cow!