Basic Precautions before Using Magnets
Proterial, Ltd.
Please read and understand the following precautions before using a magnet safely. Whenyou fail to follow the precautions, bodily injury or property damage may occur and/or theoriginal function of the magnet may not be obtained.

(6) Never cut, machine or grind a magnet or disassemble a magnetic circuit. These operations may cause
deterioration of the magnet characteristics, chips and/or cracks, etc. We do not guarantee the magnet quality insuch cases.
(7) A magnet is hard, and fragile. When it is exposed to vibration or shocks such as an automotive use, design theproper structure to avoid displacement of a magnet even if the magnet is broken.
(8) When you use an adhesive agent, verify the type, quantity, gluing conditions, strength, and other

Precautions in Generalcharacteristics of the adhesive agent, including surface condition of the magnet(cleanliness, surface roughness(1) Never bring a magnet near a person with a pacemaker or other electronic medical equipment because normal
operation of the equipment may be affected and the person may be exposed to a life threatening risk.
(2) Never swallow a magnet. If swallowed, there is a risk of suffocation or perforation of the stomach or intestines
due to magnetic attractive force with other magnets or magnetic materials. Consult a doctor immediately if amagnet is swallowed. Keep a magnet out of the reach of a child or a mentally impaired person.
(3) Never drink water or other liquid that contacts with a magnet. The constituents of a magnet may dissolve in thewater or other liquid.

etc.), and its reliability.
(9) When a magnet is used on the surface of a high-speed rotation body, such as a rotor, design properly to ensure
safety even if the magnet is broken.
(10) Processes such as press fitting or thermal insertion may be the cause of a crack or fracture of a magnet andother components, and deterioration of magnetic characteristics. Verify the process with samples beforehand.
(11) Flux leakage of the magnetic circuit may influence other equipment. Design the magnetic circuits to reduce
flux leakage when possible.

(4) If you have a metal allergy, your skin may get rough and become red by contacting with a magnet. To avoid
such symptoms, you must avoid skin contact with a magnet.
(5) Never bring a magnet near magnetic recording media (for example, a magnetic tape, a floppy disk, a pre-paid
card, a ticket, a credit card, or an ATM card). It may cause damage to the media and loss of data.
(6) Never bring a magnet near an electronic device, video equipment, communication equipment, etc. such as

Precautions in Handling and Assembling(1) When a magnet is magnetized, a strong attractive force or repulsive force arises between the magnet andother magnetic materials (magnet, yoke, rotor, stator, jig fixture, tool, etc.). A user's hand or finger may besandwiched between the magnet and other magnetic materials during handling or assembling. Also you may

an electronic clock, a cathode-ray tube(CRT), or a mobile phone, to prevent a malfunction or failure.

be injured by a loss of balance due to the attractive or repulsive force. Use appropriate jigs and take special(7) Never bring a magnet without magnetic shields in an airplane to prevent a malfunction or a breakdown.

care in handling a magnetized magnet. A magnetized magnet should be covered with a non-magnetic material
such as wood or thick plastic, and labeled as magnetized.

Precautions in Design(2) The sharp edge of a magnet may injure your finger. Protect fingers when needed.

(1) Magnetic characteristic values in anisotropic magnets are greatly depending on the easy magnetizing direction.

(3) When a magnet is magnetized in a solenoid coil, the magnet may fly out from the inside of the solenoid coil

Consider the anisotropic direction when designing.
(2) Magnetic characteristic values shown in the catalog are not guaranteed values. Magnetic characteristic values
may vary as a result of the size or the shape, etc. Confirm the design work beforehand with a prototype
sample.

unexpectedly. It can be the cause of injury. Use a proper jig fixture and restrain the magnet inside of thesolenoid coil for safety.
(4) When magnetized magnets are stacked, it is difficult to separate them, and chipping or a crack may occur. It isrecommended to use spacers between the magnets. The stacked magnetized magnets are similar to one big(3) Demagnetization is greatly related to the magnet shape, the operating point, and the exposed temperature.
Refer to the temperature characteristic curves to avoid demagnetization during assembling or operation.
(4) When the customer magnetizes a magnet, apply enough magnetic field to fully magnetize corresponding to themagnet. Take special care during handling.
(5) When a magnet is cut, machined or ground, fine magnet powder will be produced. Such fine metal powder ofthe rare-earth magnet(including bonded magnet) is inflammable, and it may ignite spontaneously. Follow thematerial and the coercive force. When the applied magnetic field is not strong enough, the designed magnetic

below notes about fine metal powder.

characteristic may not be obtained. Consult us about the required magnetic field for full magnetization.

(a) Never bring fire or flammable material near Neodymium or Samarium system magnet powder.

(5) Avoid exposing a magnet to the following environments. In such environments, the deterioration of corrosion
resistance, magnetic characteristics, and/or strength of a magnet may happen. The critical condition depends
on the material and the surface treatment of each magnet. Please consult us about rust prevention beforehand.
(a) Corrosive gas atmosphere (Cl2, NH3, SOx, and NOx, etc.)(b) Conductive environments (in water containing electrolytes, etc.)(c) Hydrogen atmosphere(c) Prepare sand or dry-chemical fire extinguisher to extinguish fire just in case of fire.
(d) Cover with sand immediately and keep away from flammable material when ignition happens.
(6) When a magnetized magnet is placed near an opposing or alternating magnetic field, demagnetization mayoccur.
(7) A magnetized magnet attracts magnetic particles. Use a clean work place. A precise motor may need wet(d) Acid, alkaline, or organic solvents, etc.

cleaning after assembly.

(e) In oil or water(f)(b) Never use vacuum cleaner to avoid electrostatic ignition.

(8) When an adhesive agent is used to glue a magnet to a yoke (or similar material or parts), choose the proper

High temperature and/or humidity environments(g) Radiation environments exceeding the background level.
p. 1/4adhesive agent and the bonding method to minimize mechanical stress. Residual stress may cause a crack ora fracture of the magnet with a small mechanical impact.
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(9) A mechanical impact may be a cause of a fracture, a crack and chipping of a magnet. Take special care during

Table 1

Storage Period

handling of a magnetized magnet. Such a crack or a chipping may deteriorate the magnetic characteristic, themechanical strength or the corrosion resistance. A broken piece of magnet may injure your eyes or body.

TemperaMagnet Material

Coating

Packaging

Stock Period

Humidity
tureNickel Coating

Plastic Bag etc.

6 months max.

10 ~ 40

Precautions in storageRare-earth magnet

Aluminum Coating(Typicalafter ex-Works(deg. C)

(1) Store magnets in a place without a mechanical impact.

Epoxy Coating

Packing)(without unpacking)(2) Keep the packaging materials of magnets dry.

Titanium

Keep the temperature above the dew point to prevent rust during storage.

Nitride Coating

Avoid water (rain, water used in the factory, etc.) from contacting the packaging material.

Chemical Conversion

Vacuum3 months max.

M-1 Treatment

Packing

after ex-Works(3) Storage period is recommended to follow the below table 1.
If storage period of the magnet has passed (in case ferrite magnet, one year after ex-Works), it isrecommended to confirm the appearance and magnetic properties of the magnet before using.

(without unpacking)Uncoated
Ferrite magnet

Uncoated(4) Verify of magnetized magnets to avoid demagnetization.

30 ~ 85 %RH

CorrugatedIndefinite

cardboard-10 ~ 4030 ~ 85 %RH(deg. C)

packing etc.

Special notes for each Magnet Material〔A〕Rare-earth magnet

Request for prior consultation(1) The alloy powder of a rare-earth magnet is designated under the Fire Service Law of Japan, as a Class 2

Please consult us before designing a new product with a magnet.

(combustible solid) Type 1 hazardous substance in Japan. Since fine powder produced by friction during theuse of a magnet is inflammable, and may ignite spontaneously, never use a magnet in such a way that will

4th-Jan.-2023

generate magnet powder.

Document No. GD-05J-02-2(2) If such powder is produced, never leave the powder in the air, but store the powder in a metal container filledwith water. When Neodymium or Samarium magnet powder contacts water, hydrogen may be produced. Takespecial care to prevent hydrogen ignition.
(3) Magnetic flux of a Neodymium magnet is deteriorated around and below liquid nitrogen temperature. Consider
this when designing a low temperature application.

〔B〕Ferrite magnet(1) Consider the decrease of intrinsic coercivity at low temperature to avoid demagnetization.
(2) A ferrite magnet is especially hard and fragile. When it is exposed to vibration or impacts, design the structure
properly.
(3) When thermal shock is applied to a magnet, magnet breakage may occur. Never expose a magnet to thermal
shock such as a rapid heating or cooling speed.
(4) If magnets rub against each other during transportation, magnet powder may be seen on the surface.

〔C〕Bonded magnet(1) When a bonded magnet is heated, the magnetic characteristics may be deteriorated. The heat softens andtransforms the binder material of the magnets. Mechanical strength may be decreased by the embrittlement
phenomenon under high or low temperature. Consult us about the operating temperature.
(2) Heat may decompose the binder and the coating material and generate hazardous and corrosive gas.
(3) The swelling phenomenon with moisture absorption or organic solvent may cause a change in dimensions anda decrease of the mechanical strength. Consult us beforehand.
(4) Some magnetizing and demagnetizing conditions using an air core coil can heat up a magnet, and it may burnyour skin.
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