Yes, if you package them appropriately. You have the following
- Arrange magnets antiparallel
- Increase the distance between magnets and package
- Shield magnets with iron sheets
If you airfreight the package, you need to adhere to strict
rules. See airfreight.
If you send the package with regular mail, the rules of the
postal service apply, which are different in every country.
Some don't even have regulations regarding the shipment of magnets.
Nevertheless, we recommend considering a few rules, since
improper packaging can lead to shipping problems. You could
damage items in other packages (credit cards, hard discs, monitors,
etc.) or cause disruptions with the sorting machines of the
postal service. Your package could also get caught on a metal
piece and content could be pulled out.
To avoid such damages you should package the magnets appropriately
for shipping. You have three possibilities that you can
apply separately or combined:
1. Arrangement of Magnets
If you send several magnets together you can massively reduce
the magnetic field through the proper arrangement of magnets
within the package. Two or more magnets should be arranged in
a way that half of the magnets are parallel to the other half,
the poles pointing in opposite directions.
For instance, if you want to send 50 disc magnets with a
diameter of 10 mm and a height of 3 mm, these basically arrange
themselves into a "bar" of 50 x 3 = 150 mm length.
However, you should not ship this bar like that, but break it
up in the middle, so that the north poles of 25 magnets point
into one direction and the other half lays parallel to them,
but with the north pole pointing in the other direction. This
way, the magnets will be "short circuited" and the
magnetic field of the package will be almost zero. Naturally,
you can arrange four, six or more "bars" parallel
to each other.
If you only have 2 magnets to send, it is possible that this
arrangement is not stable, meaning that the magnets don't want
to stay in this anti-parallel position. You can arrange the
magnets on a piece of metal sheet - one magnet with its north
pole towards the metal sheet, the other one with its south pole
towards the metal sheet. This way, the magnets can be stabilised
and the magnetic "short circuit" is even better with
the metal sheet, meaning the magnetic field will decrease massively.
Several sphere magnets can be arranged in a circle in order
to neutralise the magnetic field.
The goal of the arrangement has to be that, if possible,
the same amount of north poles and south poles of the individual
magnets point into one direction.
2. Create Distance
The magnetic field of a magnet decreases with increasing distance
very quickly. Therefore, it is advisable to pack a rather big
package and position the magnets in the middle of it. It doesn't
matter if you fill up the space with paper, Styrofoam, bubble
wrap, cardboard or wood. Except for sheet steel, other materials
are no barriers for magnetic fields. Only the increased distance
is responsible for the reduction of the magnetic field. Of course,
you'll have to retain the magnets in the middle of the package,
so they won't travel towards the sides of the package during
the course of the transport.
Therefore, the shipping of bigger magnets in an envelope
is not advisable, since the distance to the outer surface is
3. Shielding with Sheet Steel
If the "cheaper" methods of neutralisation or oversized
packaging are not sufficient, you are left with utilising sheet
steel for shielding. Sheet steel can be bent around a big magnet.
It is not necessary that the sheet and the magnet touch each
other, but it is important that the sheet steel induces a "short
circuit", meaning that it reaches from the north pole to
the south pole of the magnet. If you only place a sheet on the
north pole and another one at the south pole and the sheets
are not connected, this doesn't produce any shielding. The ideal
shielding constitutes a box of sheet steel that totally encompasses
the magnet. The stronger the magnet and the more complete the
shielding should be, the thicker the sheet steel would have
to be, so it does not reach a magnetic saturation and can induce
a "magnetic short circuit".
Paper Clip Test
In order to check if a package is not overly magnetic, its
surfaces would have to be measured with a teslameter and an
acceptable critical value would have to be determined. This
is often not possible. An every-day-life test is the paper
clip test: You put a paper clip to all sides of the package
and it should not stick, but fall down. If you want to be even
stricter, you can hold the surface not upright but at an angle
of e.g. 45 degrees and see if the paper clip slides over the
entire surface. If this test is successful, you should not have
any problems during transport and the package should arrive
safely without getting caught or damaging other items.
Shipping of Different
During transport, these minimum distances between the different
magnet types need to be observed to prevent damages and mutual
demagnetisation - Neodymium and Ferrite Magnets 22mm
|Rare Earth Disc
D 25mm x T 5mm
The Pull Force is the force required to pull a magnet
free from a flat steel plate using force perpendicular
to the surface. This is the standard for testing
magnet pull strength. Air gaps and changes in surface
material will substantially reduce the effectiveness
of the pull force, or pull strength of the magnet.