| Questions about magnets |
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| [Q] |
What is a magnet? |
| [A] |
At its most basic level, a magnet is an object that
is made of materials that create a magnetic field. Magnets have poles,
at least one north pole and one south pole. |
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| [Q] |
What is a magnetic field? |
| [A] |
A magnetic field is the region in space where a magnetic force can
be detected. The magnetic field strength and direction can be measured
in terms of strength and direction. |
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| [Q] |
What is magnetism? |
| [A] |
Magnetism is the force of attraction or repulsion between substances
made of certain materials, such as iron, nickel, cobalt, and steel.
The force of magnetism, simply put, is due to the motion of electric
charges. |
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| [Q] |
What can magnets do? |
| [A] |
Magnets have several useful functions.
Based on experience with household magnets, most people know that
magnets attract materials, including iron, nickel, cobalt, and steel.
Many people also know that magnets attract magnets at opposite poles
and repel magnets at like poles. But magnets do much more.
Magnets effect electrically charged particles and electrical conductors.
Magnets have the ability transform electrical energy without losing
their own energy. These effects can perform useful functions, for
example:
- Electrical-to-mechanical effects are key in the function of
motors, loudspeakers, and equipment that requires charged particle
deflection.
- Mechanical-to-electrical effects are useful in generators and
microphones.
- Mechanical-to-heat effects facilitate eddy current and hysteresis
torque devices.
- Mechanical-to-mechanical effects attract or repulse objects.
- Other effects of magnets include magneto-resistance and magnetic
resonance.
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| [Q] |
What are rare earth magnets? |
| [A] |
The term Rare Earth Magnets is used to
refer to a group of magnetic materials whose alloys consist of one
or more of the Rare Earth elements. These materials are characterized
by exceptionally strong magnetic properties. |
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| [Q] |
What are alnico magnets? |
| [A] |
Alnico
magnets are aluminum-nickel-cobalt
magnets. They are ideal for high-temperature use, At Adams, we stock
most types of Alnico materials, and they are commonhttly supplied
as long rods or bars. A long magnetic path length to pole surface
ratio (usually 4:1 or greater) assists in providing good magnetic
performance. |
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| [Q] |
What are flexible magnets? |
| [A] |
Flexible magnets have multi-pole magnetization
patterns for maximum holding power. They are easily cut with scissors,
knives, or die cut. They are available with adhesive or colored vinyl
coating. |
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| [Q] |
What are ceramic magnets? |
| [A] |
Ceramic magnets are made from strontium
and iron oxide powders. They are generally harder, more brittle and
lighter than metal alloy magnets. Ceramic magnets have a high electrical
resistance. |
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| [Q] |
What are soft ferrite cores? |
| [A] |
Soft ferrite is a nonmetallic magnetic
material. Soft ferrite cores are used in computers, telecommunication
equipment, TVs, and a variety of industrial equipment. Adams is an
authorized distributor of Soft Ferrite cores and accessories manufactured
by Ferroxcube (formerly Philips), EPCOS (formerly Siemens), Magnetics
Inc., Neosid, and Steward. |
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| [Q] |
What are magnetic assemblies? |
| [A] |
Magnetic assemblies are up to 32 times
stronger than regular magnets and are typically made with ceramic
magnets. At Adams, we create magnetic assemblies in custom sizes,
designs, and coatings. |
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| [Q] |
What are permanent magnets
made of? |
| [A] |
Today’s permanent magnets are
made of alloys. Alloy materials include
- Aluminum-Nickel-Cobalt (Alnico)
- Neodymium-Iron-Boron (Neo magnets or "super magnets",
a member of the rare earth category)
- Samarium-Cobalt (a member of the rare earth category)
- Strontium-Iron (Ferrite or Ceramic)
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| [Q] |
How are magnets made? |
| [A] |
Magnets are made using the following
manufacturing methods:
- Calendering
- Casting
- Compression bonding
- Extruding
- Injection molding
- Pressing and sintering
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| [Q] |
What are magnetic poles? |
| [A] |
All magnets have points, or poles, where
their magnetic strength is concentrated. Those points are called poles.
We label them north and south because suspended magnets orient along
north-south planes. On different magnets, like poles repel each other,
opposite poles attract. |
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| [Q] |
What is the difference between
the north and south poles of a magnet? |
| [A] |
When suspended or allowed to rotate freely,
magnets orient themselves in a north-south direction. The end of a
magnet that points to the north is called the north pole. The point
that seeks the south is called the south pole. |
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| [Q] |
Is there a simple way to
tell which end of a magnet is the north pole? |
| [A] |
Both poles of a magnet look the same.
However, if you place a compass near a magnet, the needle that normally
points toward the north pole of the earth moves in the direction of
the magnet’s south pole. |
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| [Q] |
What does 'orientation
direction' mean? |
| [A] |
Some magnets, called oriented or anisotropic
magnets, have a preferred direction in which they should be magnetized.
The "orientation direction," also known as an "easy
axis" or "axis," is the direction that achieves its
maximum magnetism. Other magnets, called unoriented or isotropic magnets,
can be magnetized in any direction. |
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| [Q] |
Is it true that
magnetic fields are stronger closer to the magnets themselves? |
| [A] |
Yes. The strength of magnetic fields diminishes
with distance. This phenomenon can be measured with exponential equations. |
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| [Q] |
What is the difference between
permanent magnets and electromagnets? |
| [A] |
Permanent magnets emit a magnetic field
without the need for any external source of power. An electromagnet
emits a magnetic field only when an electrical current runs through
it. |
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| [Q] |
Are permanent magnets really
permanent? |
| [A] |
Magnets generally retain their magnetism
unless they are stored near power lines, other magnets, and high temperatures.
Over time, magnet materials lose a very small amount of magnetism.
For example, Samarium Cobalt magnets may lose about 1% of their magnetism
in ten years. |
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| [Q] |
Do magnets get weaker? How? |
| [A] |
Several factors can weaken the magnetism
in a magnet. If a magnet is stored close to heat, strong electrical
currents, other magnets, or radiation, it can lose its strength. Additionally,
high humidity can corrode neodymium magnets. |
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| [Q] |
Can magnets that have lost
their magnetism be re-magnetized? |
| [A] |
That depends on how the magnetism was
lost. Usually magnets can regain their original strength unless they’ve
been exposed to extreme heat. |
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| [Q] |
Can magnets be made stronger? |
| [A] |
Once a magnet is fully magnetized, it
cannot be made any stronger. |
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| [Q] |
How is magnetic strength
measured? |
| [A] |
A number of devices measure the strength
of magnets. Here are a few common devices.
- Permeameters measure the magnetic characteristics of a specimen.
- Gaussmeters measure the strength of a magnet in units called
Gauss units.
- Magnetometers measure in Gauss or arbitrary units for comparing
magnets.
- Pull Testers measure the strength of a magnet’s pulling
power in pounds, kilograms, or other force units.
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| [Q] |
What kind of magnets are
the strongest? |
| [A] |
Rare earth magnets are the strongest. |
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| Questions About Adams |
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| [Q] |
What types of magnets does
Adams Magnetic Products specialize in? |
| [A] |
We specialize in several types of magnets.
- Flexible magnets are made of thermoplastic materials and can
be bent without affecting their performance.
- Ceramic magnets, or hard ferrite magnets, are rigid and brittle
provide good magnetic performance, and are generally economical.
- Alnico, or aluminum-nickel-cobalt, magnets are ideal for high-temperature
use.
- Rare earth magnets deliver incredible strength in a small package.
- Magnetic assemblies, which are up to 32 times stronger than
magnets alone.
- We also distribute of soft ferrite cores and accessories that
are used in transformers and power supplies.
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| [Q] |
How do I contact Adams? |
| [A] |
Just call 1-800-747-7543, fax 1-800-747-1323, or email
info@adamsmagnetic.com. |
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| [Q] |
What information should I provide when
ordering? |
| [A] |
We will help you with your order. Usually we ask
for the following information.
- Size limitations of the magnet or, if available, a sketch or
drawing with dimensions and tolerances.
- Holding power or pounds pull required.
- Degree of heat involved, if extreme.
- Type of magnetic material.
- Quantities required.
- Information on what you want to use the magnet for.
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| [Q] |
Does Adams have a catalog? |
| [A] |
We have a catalog of offerings. If you would like to
order a catalog, please call 1-800-747-7543, fax 1-800-747-1323, or
email info@adamsmagnetic.com. |
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| [Q] |
How long has Adams Magnetic Products
been in service? |
| [A] |
Adams Magnetic Products was established in 1950, delivering
more than 50 years of expertise and service. |
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