Abstract: A magnetic device includes a core received in a housing and having three or more outer peripheral surfaces and having one end received in the housing and the other end facing out of the housing. Three or more magnetic members are attached onto the outer peripheral surfaces of the core and secured to the core and the housing with fasteners. The magnetic members include one pole arranged closer to the core and the other pole distal to the core, in order to increase the magnetic field intensity, and to form a unidirectional magnetic line of force, and for allowing the magnetic device to be strongly attracted onto various objects.

Abstract: A high frequency magnetic material ceramic composition including materials having the general formula (Ca, A)zCuxB8−x−zO12 is prepared. A represents Y and/or at least one element selected from the rare earth elements excluding Y; B represents metal elements which are different from A and include at least Fe and V. x has a value of 0.002<x<0.2; and z is a value of 3.0<z≦3.09. The Ca/V ratio is 2.0<Ca/V≦2.4. A irreversible circuit component containing center electrodes electrically insulated from each other in a ferrite member made of the high frequency magnetic material ceramic is provided.

Abstract: The invention relates to an armature for an electromagnetic actuator, having a guide pin that is connected to an armature plate, characterized in that the armature plate (3) is formed by a frame element (4) that comprises soft-magnetic iron and is connected to the guide pin (2), and at least one plate element (5) that comprises a soft-magnetic material and is held in the frame element (4).

Abstract: A magnetic field produced by a magnet is measured and modeled as a sum of additive components, each having a different symmetry with respect to the three-dimensional field. The sum of all the additive components completely describes the measured magnetic field, without approximation due to truncation of terms. The degree of non-homogeneity in the measured field is determined by examining the additive components individually. A shim is designed to correspond to a magnitude change of an additive component in order to improve the homogeneity of the magnetic field, such as in an MRI application. The shim is placed in a predetermined location against a metal plate that is connected to or placed near a pole of the magnet, and a plastic plate is attached to the metal plate to hold the shim in place. Grooves are machined into corresponding symmetrical plate locations to complement the shim effect.

Abstract: A flexible permanent magnet containing atomized, generally spherical rare earth magnet particles bonded in a binder resin including a nitrile rubber and precipitated amorphous silica. The bonded permanent magnet exhibits high mechanical flexibility and elasticity, good magnetic properties, and good heat aging, and the magnet powder may be mixed with the binder resin with little to no risk of combustion. In an exemplary embodiment, a permanent magnet composition includes a nitrile rubber with about 23-37% acrylonitrile content, an ethylene vinyl acetate copolymer, a precipitated amorphous silica, and atomized, generally spherical rare earth magnet particles having a size distribution including a median particle size in the range of about 35-55 &mgr;m with a standard deviation in the range of about 10-30 &mgr;m and less than about 0.1% of the particles having a diameter above about 115 &mgr;m.

Abstract: A magnetic rotating apparatus is used for connecting a body portion and a rotating portion of a foldable product. The body portion has an assembling portion while the rotating portion has a pivot portion. The rotating portion is secured to the body portion by engaging the pivot portion with the assembling portion, so that the rotating portion is allowed to pivot on the body portion and be positioned at the first stable equilibrium or the second stable equilibrium. The magnetic rotating apparatus comprises a magnetic body component situated in the assembling portion and a magnetic pivot component situated in the pivot portion. The magnetic body component and the magnetic pivot component are disposed as mates. Also, the opposite surfaces of the magnetic pivot component and the magnetic body component have the same polarity. When the rotating portion and the body portion are maintained at the first stable equilibrium, the magnetic pivot component is positioned at one side adjacent to the magnetic body component.

Abstract: The present invention provides a ring magnet made of hard magnetic material having a ring shape, which has an orientation ratio of 50% by volume or more of easy magnetization axis in the radial direction at the pole center position. The present invention also provides a method of manufacturing a ring magnet comprising a step of orientating magnetic powder of hard magnetic material, which comprises molding the magnetic powder filled in a ring shaped mold under a pressure in an axial direction of the ring, and applying magnetic field to the ring shaped mold with a magnetic field generating means disposed to the periphery of the mold.

Abstract: Disclosed is a rare earth-based sintered permanent magnet block used in the rotor of a permanent magnet synchronous motor. The magnet block of the form having an upper surface and a lower surface in parallel is provided in each of the upper and lower surfaces with at least one narrow slit having a specified incision depth, width and length so as to decrease the adverse influences of the eddy currents generated in the magnet block while the running direction of the slits in the upper surface and the running direction of the slits in the lower surface make an angle of at least 10° or, preferably, 90° so that the decrease in the bending strength of the magnet block due to the slits can be minimized without decreasing the desired eddy current-decreasing effect.

Abstract: A rare earth permanent magnet consists of 20-40 wt % of at least one rare earth element R, 0.5-4.5 wt % of boron B, 0.03-0.5 wt % of M (at least one of Al, Cu, Sn and Ga), 0.01-0.2 wt % of Bi, and the balance being at least one transition metal element T.

Abstract: A magnetic-based sensor is disclosed which can detect a linear and rotary position of a shaft whose movement is to be measured. Such sensor can operate to yield linear displacement as well as rotation. A position magnet is mounted on the shaft for measuring linear motion. A spirally wound magnet is mounted on the shaft to detect rotational motion. Both of such motions are detected by a single magnetic-based sensor.

Abstract: The present invention relates to an electromagnetic electro-acoustic transducer to be used for generating an incoming indicator tone for mobile phones and the like. A resin magnet 11 is formed with a hard magnetic material and a soft magnetic material, the lowest resonant frequency can be easily set by changing the magnetic flux density in a magnetic gap by changing the compound ratio of the soft magnetic material, a high magnetic flux density is attained by increasing the magnetic permeability of the resin magnet 11 with the soft magnetic material, thus achieving a smaller size as well as a higher sound pressure through an increase in the driving force exerted to the diaphragm.

Abstract: A magnet assembly comprising a magnet mounted for pivoting about a first axis spaced from the magnet, and rotating about a second axis that is perpendicular to and intersects with the first axis. The magnet comprising a plurality of segments each with a magnetization direction such that through a combination of pivoting and rotating the magnet projects a magnetic field in any direction at an operating point spaced from the front of the assembly. The segmented construction with segments of different magnetization directions allows small changes in the orientation of the magnet to substantially change the magnet field direction at a system operating point.

Abstract: A magnetic device for treating carbon based fuels by exposing the fuel piping to intense magnetic fields. The south magnetic poles are placed adjacent to the pipe and the flux lines in the pipe are increased by the use of permeable steel bars adjacent to the magnets and pipe. The device includes a flux path through a permeable housing and cover. The device can be installed around existing piping or inserted in the pipe line by pipe fittings.

Abstract: A pole wheel of the type driven in rotation by a shaft employs a sensor system disposed on the pole wheel for detecting rotations of the shaft. The pole wheel includes a first component in the form of a hollow magnet body and a second component that is disposed as a retaining part for the first component and is seated firmly on the shaft and is embodied integrally, for the sake of streamlined connection to the first component, with connecting means. Recesses, which for instance can be embodied in groovelike fashion, may be disposed on the second component, that is, the retaining part seated solidly on the shaft, and the first component is injected molded onto the second component, creating positive engagement connecting means comprising the material of the magnet body.

Abstract: A multipole beamline magnet (10) includes a plurality of stationary poles (12) formed of ferromagnetic material and one or more permanent magnets (14) that are disposed between the plurality of stationary poles. Each of the permanent magnets supplies magnetomotive force to two adjacent stationary poles, so that the poles produce a magnetic field in a central space (16) defined by the poles. A mechanical axis (18) of the beamline magnet is defined to extend through the central space, perpendicularly to the plane defined by the poles and the magnets. The beamline magnet further includes a linear drive (20) that is adapted to move the permanent magnet(s) perpendicularly to the mechanical axis. Thus constructed, the beamline magnet produces a high-quality field using its stationary poles, and further allows for selective adjustment of the magnetic field strength and the magnetic centerline by collectively or selectively moving the permanent magnets.

Abstract: A Neodymium-Iron-Boron permanent magnet which is substantially wider across a first axis than across the perpendicular second axis. The second axis is the axis defining the north and south poles of the magnet. At one of the poles is a permalloy cap which is substantially parallel to the first axis and inhibits the extension of magnetic flux from that pole and encourages instead a deep extension of the magnetic flux from the other pole. An aperture penetrates the magnet through the second axis which is wider at the pole away from the permalloy cap than it is at the pole adjacent to the permalloy cap. The shape of this aperture causes a distortion of the deeply extending magnetic flux lines at the pole away from the permalloy cap to be pinched inward toward the second axis rather than being parallel to it.

Abstract: A space defining structure for magnetic homogenization is disclosed. The space defining structure of this invention is specifically designed to homogenize the magnetic field within its interior space, thus minimizing a malfunctioning or damage of electronic equipment or ill-effect on living matters within houses and buildings due to a localized geomagnetic disturbance. Such a localized geomagnetic disturbance may be generated by a variety of magnetic structures, such as the interior structures of the earth's crust, for example, stratum structures, underground water and water veins, a variety of magnetic materials, a variety of electronic devices or the reinforcing bars of the houses or buildings. The space defining structure for magnetic homogenization of this invention consists of a magnetic field focusing member 1 forming the bottom wall of the space structure.

Abstract: The invention provides a deflection yoke having two centering magnets mounted thereon for the adjustment of centering. Each of the centering magnets is molded in an annular form from a resin material containing a finely divided magnetic material, the centering magnet having two portions opposed to each other as displaced from each other by 180 degrees about a center axis of the annular form thereof and magnetized to an N pole and an S pole respectively, the content of the magnetic material varying circumferentially of the annular form, the distribution of the content being symmetrical about a straight line orthogonal to a straight line through a center point of the N pole and a center point of the S pole. The magnetic force for the adjustment of centering can be eliminated by the two magnets mounted in combination.

Abstract: Magnets, which have a surface facing a coil, through which current flows, generate magnetic flux to be emitted toward the coil in the direction of the normal line of the surface of the magnets toward the coil, the magnets having a recession or protrusion formed at the center thereof. The magnets form magnetic flux to be regularly generated and thus can generate uniform electromagnetic forces through interaction with current.

Abstract: A ring magnet having improved linearity and/or peak value in a pace magnetic flux density distribution, comprising at least one first radially anisotropic region having a radial anisotropy direction of 89° or more relative to a center axis thereof, and at least one second radially anisotropic region having a radial anisotropy direction of 40° or more and less than 89° relative to a center axis thereof, the first and second radially anisotropic regions being arranged along the center axis such that a space magnetic flux density distribution on an inner or outer surface of the ring magnet has increased linearity and/or peak value.

Abstract: An imaging apparatus, such as an MRI system, contains at least one layer of soft magnetic material between the yoke and each permanent magnet. This imaging apparatus may be operated without pole pieces due to the presence of the soft magnetic material. The permanent magnets may be fabricated by magnetizing unmagnetized alloy bodies after the unmagnetized alloy bodies have been attached to the yoke.

Abstract: The present invention provides a composite magnetic body containing metallic magnetic powder and thermosetting resin and having a packing ratio of the metallic magnetic powder of 65 vol % to 90 vol % and an electrical resistivity of at least 104 &OHgr;·cm. When a coil is embedded in this composite magnetic body, a miniature magnetic element can be obtained that has a high inductance value and is excellent in DC bias characteristics.

Abstract: The present invention provides magnets having a metallic pin mounted therein with high bond strength and with high reliability and exhibiting good productivity. It also provides magnets in which the bond strength of the metallic pin remains high even at high temperatures or in organic solvents. Specifically, the present invention relates to a magnet having a metallic pin mounted therein without using an adhesive, and this magnet can be made by sintering the magnet and the metallic pin at the same time.

Abstract: A Neodymium-Iron-Boron permanent magnet which is substantially wider across a first axis than across the perpendicular second axis. The second axis is the axis defining the north and south poles of the magnet. At one of the poles is a permalloy cap which is substantially parallel to the first axis and inhibits the extension of magnetic flux from that pole and encourages instead a deep extension of the magnetic flux from the other pole. An aperture penetrates the magnet through the second axis which is wider at the pole away from the permalloy cap than it is at the pole adjacent to the permalloy cap. The shape of this aperture causes a distortion of the deeply extending magnetic flux lines at the pole away from the permalloy cap to be pinched inward toward the second axis rather than being parallel to it.

Abstract: Disclosed are a method of measuring ESR in a sample located outside a resonator using the B1 leaking to the exterior from the end of the resonator; and an ESR device comprised of at least a resonator capable of applying a B1 leaking from the end of the resonator to a sample located outside the resonator, and a magnet located on the resonator side of a plane containing the end of the resonator that is capable of applying a B0 and a modulation field. These inventions enable ESR measurement of the interior of large samples.

Abstract: A magnetic apparatus for oil filters including a magnet removably coupled with respect to the oil filter for preventing loose metal particulate from circulating within an engine.

Abstract: A pole wheel of the type driven in rotation by a shaft employs a sensor system disposed on the pole wheel for detecting rotations of the shaft. The pole wheel includes a first component in the form of a hollow magnet body and a second component that is disposed as a retaining part for the first component and is seated firmly on the shaft and is embodied integrally, for the sake of streamlined connection to the first component, with connecting means. Recesses, which for instance can be embodied in groovelike fashion, may be disposed on the second component, that is, the retaining part seated solidly on the shaft, and the first component is injected molded onto the second component, creating positive engagement connecting means comprising the material of the magnet body.

Abstract: In an arrangement for adjusting the spatial dependence of a magnetic field in a working volume of a main field magnet (19) by means of ferromagnetic field shaping elements (16), the field shaping elements (16) are formed from foils (1, 5, 7, 8) and/or sheet metals (10) having openings (2, 3) whose shape, position and size are selected such that the shape and the amount of the remaining ferromagnetic material produces a desired spatial dependence of the magnetic field in the working volume of the main field magnet for appropriate positioning of the foils (1, 5, 7, 8) and/or sheet metals (10) relative to the working volume of the main field magnet.

Abstract: A magnetic cylinder for holding printing plates, embossing plates, die-cutting plates or the like has a plurality of pockets or recesses formed on its outer surface, each of the pockets or recesses containing magnetic elements of permanent bar magnets and interposed pole pieces with the pockets offset circumferentially from one another so that the magnetic holding field will armature with the plate placed on the cylinder at least in part over the entire width and length or breadth of the plate to ensure that the entire plate including the leading and trailing edges are held securely in place while the cylinder rotates.

Abstract: The present invention relates to a plastoferrite magnetic profile suitable to act as the magnet in generators and electric motors characterised in that it is formed by extrusion with substantially convex section.

Abstract: Apparatus and methods for the adjustment of a magnetic field produced by permanent magnet arrangements facing each other across an air gap include a series of ferromagnetic shim blocks individually adjustably positionable within the magnet arrangements to adjust the strength and uniformity of the magnetic field. A backing plate to which the permanent magnets are attached has channels within which adjusting elements are used to move the shim blocks with relation to the permanent magnets, preferably toward or away from the air gap. Shim blocks are arrange in selected geometric arrays and shapes responsive to the geometry of the magnet arrangements and may be formed as toroidal shapes or as individual blocks of varying sizes.

Abstract: A bi-chromal ball production apparatus and method where the bi-chromal ball material is fed from opposite sides of the disk, reconfiguring the internal geometry of the apparatus, and precisely configuring the bi-chromal ball material feeding slit. The bi-chromal ball production apparatus has a disk that rotates, a first supply structure that supplies a first bi-chromal ball material to the disk from a first direction, a second supply structure tube that supplies a second bi-chromal ball material to the disk from a second direction and a motor that rotates the disk. The bi-chromal ball production apparatus includes a first reservoir and a first slit defined by the disk and a top body, a second reservoir and a second slit defined by the disk and a bottom body. An inner surface of each of the first and second reservoir is parabola shaped.

Abstract: A magnetic biological particle separation device comprising a permanent magnet structure substantially surrounding a vessel containing a liquid and a biological sample in colloidal suspension in the liquid is described. The magnetic separation device comprises a window through which to view the liquid. The permanent magnet structure comprises a plurality of permanent magnets arranged in such a manner to provide for superpositioning of the external magnetic field generated by each magnet. The external magnetic field acts on magnetic beads attached to the biological sample, causing the sample to move toward the inner wall of the vessel. The permanent magnets do not completely surround the outside of the vessel to allow the liquid to be poured out of the vessel, substantially leaving the sample.

Abstract: A device for transporting particles of a magnetic material in a selected direction, having a support member having a support surface for supporting the particles, the support surface extending in a selected direction, a magnet arranged to generate a magnetic field retaining the magnetic particles on the support surface, the magnetic field having at least one region of reduced field strength at the support surface relative to a field strength of the magnetic field at the support surface outside said region, and drive means for moving each region of reduced field strength relative to the support surface in a direction having a component in the selected direction.

Abstract: A device for attaching a laminar object such as a poster to a wall includes a plate having a rear face which is attachable to a wall and a boss which protrudes from a front face of the plate. The plate may include a layer of ferromagnetic material such as steel and may be attached to the wall by a plastic holding composite, a nail or pin or by adhesive. A hole may then be punched in a corner of a poster or other laminar object and that hole is placed over the boss which then supports the poster from the wall. A keeper which is may be made from a rubberized magnetic material and includes a through hole which is approximately the same size as the boss, is placed over the plate to retain the poster in place. Further weak magnetic attraction between the retainer and the ferromagnetic plate or an interference fit helps keep the retainer attached over the boss and retain the poster on the wall except in drafty conditions where the keeper releases the poster.

Abstract: A class of antibacterial and antibiofilm bonded permanent magnets having: superior (BH)max comprising: permanent magnet particulate, binder and a cationic antibacterial and antibiofilm substance responsive to the magnetic field of said magnet.

Abstract: A container for a magnet, in the form of a box, has an outer clear plastic shell and an inner box preferably of opaque molded material, sized to fit closely within the clear outer shell. A magnet fits closely within the inner box. Between the outer and inner boxes, at an outer face of the composite container, a sheet of decorative or graphic material can be retained, sandwiched between walls of the outer and inner boxes. The inner and outer box elements preferably are retained together by snap-in structure, which in one preferred embodiment comprises nipples molded on the inside surface of side walls of the outer box, to be engaged in dimples or recesses at corresponding positions on the outer surface of the inner box's side walls. Both the inner and outer box elements are open at one side, and the magnet can be retained in the inner box by adhesives, fasteners or other appropriate connection devices.

Abstract: A hollow magnet body with an annular auxiliary body and produces them as a combined component using an injection molding process. In this connection, an inner diameter of the annular auxiliary body is embodied as greater than a diameter of the associated shaft so that a tubular section extends out from the material of the hollow magnet body between this shaft and the annular auxiliary body and is suited for the production of a press fit. As a result, the annular auxiliary body made of metal supplies the main component of the pressing forces, thus counteracting the danger of the hollow magnet body splitting.

Abstract: A magneto-spring structure includes a lower frame and an upper frame vertically movably mounted on the lower frame via a link mechanism. The upper and lower frames have respective permanent magnets secured thereto, with like magnetic pole opposed to each other. The link mechanism includes a plurality of links and a connecting member for rotatably connecting them via a bearing. The links are made of non-magnetic material, while the bearing is made of ferromagnetic material.

Abstract: Ferromagnetic material of an elongated object, such as a fiber optic cable, is permanently magnetized in a manner that results in a substantially cylindrically symmetric radial external magnetic field around the object. The produced magnetization is substantially greater than natural magnetization of the ferromagnetic material by the earth's magnetic field. The radial external magnetic field varies periodically along the length of the object. If the wavelength of the periodic variations is long compared to the width (diameter) of the object, the strength of the radial external magnetic field decreases approximately inversely with distance from the object for distances that are small compared to the wavelength. The periodic magnetic field variations may have a square wave or a sine wave pattern, for example.

Abstract: A bulk exchange-spring magnet 12, a method of producing the same, and a device 20 incorporating the bulk exchange-spring magnet are disclosed. The magnet includes magnet powders 10 having hard and soft phases, and boron and oxygen atoms which cohere in boundary areas 16 between grains 14 of the densified magnet powders 10. In a production method, the magnet powders 10 are compacted so as to incorporate boron and oxygen atoms into the boundary areas 16 and are heated under a compacted state of the magnet powders at varying operating temperatures for a given time period. This results in formation of a highly densified magnet at a lower potential operating temperature for a shorter time period without the grain growth. The device 20 includes the bulk exchange-spring magnet 12 containing the boron and oxygen atoms cohering between the grains of the densified magnet powders.

Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.

Abstract: An animal pill magnet having a casing, core pieces, and at least one magnet. The casing comprises a first capsule half and a second capsule half that are joined together with a single joint to enclose the core pieces and at least one magnet.

Abstract: The purpose of the present invention is to present a thin-plate magnet with a fine crystalline structure that is 70 &mgr;m to 500 &mgr;m thick, making miniature, thin magnetic circuits possible, and has, as cast, an inherent coercive force iHc of 2.5 kOe or higher and residual magnetic flux density of 9 kG or higher and a performance-to-cost ratio rivaling that of hard ferrite magnets when Nd—Fe—B fine crystalline permanent magnets with a low rare earth content that are a mixture of a soft magnetic phase and a hard magnetic phase are produced. iHc can be increased to 2.

Abstract: A releasing magnet for anti-theft devices for sales goods with a permanent magnet and a housing having a disc-shaped collar and a fastener for securing the housing to a table. The housing is made of plastic and at least almost surrounds the permanent magnet which prevents corrosion and allows the releasing magnet to be washed so that its use is hygienic.

Abstract: A bulk amorphous metal magnetic component has a plurality of laminations of ferromagnetic amorphous metal strips adhered together to form a generally three-dimensional part having the shape of a polyhedron. The component is formed by stamping, stacking and bonding. The bulk amorphous metal magnetic component may include an arcuate surface, and an implementation may include two arcuate surfaces that are disposed opposite each other. The magnetic component may be operable at frequencies ranging from between approximately 50 Hz and 20,000 Hz. When the component is excited at an excitation frequency “f” to a peak induction level Bmax, it may exhibit a core-loss less than “L” wherein L is given by the formula L=0.0074 f (Bmax)1.3 +0.000282 f1.5 (Bmax)2.4, said core loss, said excitation frequency and said peak induction level being measured in watts per kilogram, hertz, and teslas, respectively.

Abstract: A bond magnet comprises a molded body in which a mixture of flake of magnet material comprising rare earth element-iron-nitrogen as main component, TbCu7 type crystal phase as a principal phase and a thickness of less than 200 &mgr;m a binder is compression molded. A compression molded body constituting a bond magnet has a density of 6×103 kg/m3 or more. In the step of compression molding a mixture of magnet material and binder, pressure is applied a plurality of times, or pressure is applied while rotating a punch and die, or the binder is cured while applying pressure to obtain such a bond magnet with good reproducibility. Such a bond magnet has excellent magnetic properties and corrosion resistance.

Abstract: An Fe—B—R based permanent magnet has a metal oxide film having a thickness of 0.01 &mgr;m to 1 &mgr;m on its surface with a metal film interposed therebetween. Thus, the film is excellent in adhesion to the surface of the magnet. Even if the permanent magnet is left to stand under high-temperature and high-humidity of a temperature of 80° C. and a relative humidity of 90% for a long period of time, the magnetic characteristic of the magnet cannot be degraded. The magnet has a thermal shock resistance enough to resist even a heat cycle for a long period of time in a temperature range of −40° C. to 85° C., and can exhibit a stable high magnetic characteristic. Therefore, it is possible to produce an Fe—B—R based permanent magnet having a corrosion-resistant film free from hexa-valent chromium.

Abstract: A magnetically detectable plastic pipe that can be located and identified when buried in earth is provided. The pipe contains particles of a ceramic ferrite which are magnetically polarized radially in the pipe in a helical pattern which periodically repeats along the pipe length.

Abstract: An anisotropic permanent magnet with an improved surface magnetic field peak value is provided, which has at least one active surface and is oriented and magnetized simultaneously in such a manner that axes of easy magnetization of magnetic powder constituting the permanent magnet pass from the active surface through an interior of the magnet to return to the active surface, wherein a standard magnetic pole and a background opposite magnetic pole are present as an island and a sea, and the ratio of an area of the standard magnetic pole to an area of the background opposite magnetic pole is 9 to 90:91 to 10. Also, a permanent magnet for attraction with an improved attraction force is provided, wherein a total area &Sgr;S of an S pole surface and a total area &Sgr;N of an N pole surface satisfy a relationship: 0.5×&Sgr;S≦&Sgr;N≦2.0×&Sgr;S or 0. 5×&Sgr;N≦&Sgr;S≦2.0×&Sgr;N.