Permanent magnet supply direction
1) Permanent magnet supplied under two conditions,Magnetized or no magnetized, is usually not marked its polarity. If the user require, we could mark the polarity by the means agreed on. When pacing the order, the user should inform the supply condition and if the mark of the polarity is necessary.
2) The magnetization field of permanent magnet is related to the permanent magnetic material type and its intrinsic coercive force. If the magnet need magnetization and demagnetization, please contact with us and ask for technique support.
There are two methods to magnetize the magnet: DC field and pulse magnetic field.
There are three methods to demagnetize the magnet:demagnetization by heat is a special process technique.demagnetization in AC field. Demagnetization in DC field. This asks for very strong magnetic field and high demagnetization skill.
3) geometry shape and magnetization direction of permanent magnet: in principle, we produce permanent magnet in various shapes. Usually, it includes block, disc, ring, segment etc. The detailed illustration of the magnetization direction is below:
As for the ring magnets magnetized radially (B),only the isotropic magnetic ring is available. The anisotropic ones are still in research.
4) Size and tolerance of the permanent magnet: Except for the dimension in the direction of magnetization, the maximum dimension of the permanent magnet is not exceed 60mm, which is limited by the orientation field and sintering equipment. The dimension in the magnetization direction is up to 200mm.
Usually the permanent magnet should be ground. The tolerance after grinding is usually +/-0.05. Tolerance +/-0.02mm is available too, but the cost will be higher.
We suggest the user to refer to our national military standard GJB2453rare earth permanent magnet general criterion in the design of the tolerance of the permanent magnet.