Abstract: A developing roller is made up of a magnet member and a sleeve surrounding the magnet member. A sophisticated magnetic characteristic including a repulsive pole can be easily formed on the surface of the sleeve. The repulsive pole causes a developer to be sharply released from the surface of the sleeve. A developing device including the developing roller is also disclosed.

Abstract: A brushless permanent-magnet direct current motor has a permanent magnet which is magnetized to create an offset angle between detent and mutual torques for providing sufficient starting torque for all relative orientations between the stator and the rotor of the motor. This is accomplished by providing a permanent magnet in which the global magnetization of the magnet has been disrupted by the application of a local magnetic field to a portion of the magnet, thereby to provide a magnetic anomaly in the global magnetization. Also, a method of magnetization of the magnet is described.

Abstract: A motor vehicle dashboard has a support face. Air ducts are carried by the dashboard for taking air into the cabin of the vehicle. Each duct has a longitudinal slot which is bounded by two adjacent edges, so that the duct has a transverse cross section in the form of an open annulus. The duct has two external engagement faces on either side of the longitudinal slot, and is fixed to the support face of the dashboard by means of these engagement faces. The duct is made by moulding in a suitable deformable material such that it can be stripped from the mould by opening out the slot, after which the slot is closed up again.

Abstract: The present invention offers a production method for anisotropic resin-bonded magnets with precise dimensions in high productivity. It comprises the aligning step in which the preform is preliminary compression-molded in the preforming molding die 22 in the preforming press 20 with an applied magnetic field to align the magnetization direction of the magnet powder at a temperature in which the thermosetting resin in the compound becomes liquid state, the transferring step in which said preform is transferred from preforming press 20 to densifying molding die 32 in a densifying press 30, and densifying step in which said partly cured preform is compression-molded by applying pressure in a densifying press 30 to obtain desired shape of magnet.

Abstract: A plastic magnet injection molding machine comprising a pair of exciting coils respectively embedded into a fixed plate and a movable plate along with respective seats and a metal mold including ferromagnetic central members and non-magnetic peripheral members is provided. With such an arrangement, the machine can anisotropically process magnet powder with enhanced efficiency by energizing the coils. Both the fixed plate 2 and the movable plate 4 of the machine are made of ferromagnetic metal. The exciting coils 7, 8 are respectively embedded into the plates at the oppositely disposed sides thereof along with the non-magnetic annular seats 9, 10 surrounding the respective exciting coils. The fixed mold 12 and the movable mold 13 of the metal mold 11 of the machine include respective central members 14, 15 made of ferromagnetic metal. The central members 14, 15 of the fixed and movable molds are respectively made to abut corresponding central portions 2a, 4a of the fixed plate 2 and the movable plate 4.

Abstract: A blocking device for filling a cavity in a hollow structural member includes a foamable material, and magnetic member embedded on a surface of the foamable material, the magnetic member is secured within the hollow structural member and the foamable material is foamed and expanded by the application of heat so that the cavity is filled.

Abstract: A die for extrusion molding a resin bonding magnet. In the production of the magnet, a molten mixture of a magnetic powder and a resin are introduced into a cavity between an outer die and a mandril to which a magnetic field is applied. A steep temperature gradient along the die axis direction of the molten mixture and the cavity is achieved by making the outer die of a multiple layer structure along the die axis direction, utilizing two or more axially adjacent blocks or sheets made of the same or different materials whereby fluidity of the molten mixture is sufficiently high at the inlet of the cavity to enable the magnetic powder in the molten mixture to be sufficiently orientated in the direction of the magnetic field and then the molten mixture is cooled to a solidified state so that the orientation of the magnetic powder is not disturbed, thereby producing a magnetic having high magnetic properties.

Abstract: A mass of ferromagnetic particles moldable into stable, high strength, magnetic cores useful in thermally and chemically hostile environments comprising an iron core and a continuous layer of polyetherimide, polyethersulfone or polyamideimide spray coated onto the surface of each particle. A method of preheating and molding the particles is disclosed.

Abstract: A hollow, member which serves as a cylinder having an inner configuration which matches the outer configuration of a magnet roller to be manufactured, is mounted in a metallic mold, and then the metallic mold is clamped. A molten resin containing magnetic particles is injected into the mold cavity of hollow member through a runner. Magnetic lines of force are applied to a roller type resin magnet, and such an application is continued. Before the roller type magnetic resin is fully cured, the mold is opened. Then, the magnetic members of a movable mold member 1 are separated from the magnetic members of a stationary mold member so that the distribution of the magnetic flux passing through the hollow member is changed. When the roller type resin magnet is fully cured by cooling, a magnet roller having two pairs of magnetic poles with different surface magnetic flux densities can be obtained.

Abstract: An iron powder composition comprising an iron powder coated with a substantially uniform coating of a thermoplastic material and admixed with a boron nitride powder and a method of utilizing the mixture to produce a magnetic core component is provided. The iron powder mixture is formulated with up to about 1% by weight of boron nitride which reduces the stripping and sliding die ejection pressures during high temperature molding and also improves the permeability of the magnetic part over an extended frequency range.

Abstract: A process and apparatus for permitting the magnetization of flexible hard magnetic materials in the form of sheets or strips, such as magnetic rubber, wherein opposing arrays formed from alternating magnetic disks and flux conducting elements are use in sets of two with opposing polar moments such as to induce a magnetic flux in the gap between the discs. The width of the magnetic disk and flux conducting elements, respectively, are selected to optimize the magnetic pull strength of the material. At the array ends are flux conducting elements that are about 1/2 (i.e., from about 0.25 to about 0.75, and preferably from about 0.4 to 0.6) of the width of the internal flux conducting elements. A material to be magnetized is passed between the array sets in contrast with both disks and consequently imprinted with magnetic poles. The magnetized properties of the material is enhanced by passing the material through a second set of arrays which are axially offset with respect to the first set of arrays.

Abstract: A lateral orientation type of anisotropic permanent magnet having a face of magnetic application and at least one lateral face adjacent to the face of magnetic application. An axis of easy magnetization of particles of a magnetic powder constituting the permanent magnet is oriented substantially along lines from the lateral face toward the face of magnetic application to increase the peak value of the surface magnetic flux density at the face of magnetic application.

Abstract: A magnet is formed as a ring magnet and magnetized by radial application of a magnetic field while the intensity of the magnetic field is changed periodically along the circumference of the ring magnet to give a circumferentially sinusoidal waveform distribution of magnetic flux density to the ring magnet in the magnetized state of the magnet.

Abstract: A magnetically detectable plastic pipe having magnetic particles distributed in the wall of the pipe so that it is easily detected from the surface when buried in the ground, in a wall in concrete or other distant or relatively inaccessible locations. The magnetic particles are preferably distributed in the wall of the pipe by extrusion with the plastic at the time the pipe is formed and the pipe is passed through a magnet to magnetize the pipe diametrically with one pole on one side of the pipe and the other pole diametrically opposite. The pipe magnetization polarity may be selectively reversed to encode a unique magnetic signature to the pipe. Changing the magnetization polarity may also be used to encode data on the pipe. The pipe may be rotated and passed linearly through the magnet, or the magnet may be rotated around the pipe to produce a spiralled diametrically oriented magnetic structure. Another magnetic material used is strontium ferrite.

Abstract: A plastic binder is milled to a powder, preferably having a particle size equal to the mean size of flakes of permanent magnet material, and dry mixed with the magnetic flakes. A molding fixture is heated to a temperature higher than that of the melting point of the plastic binder. A rotor core, having a rounded upper edge for molding a thin cylindrical magnet thereon, of solid or laminated soft magnetic material is prepared and placed in the molding fixture and brought up to the molding temperature. The mixture is poured in measured amounts into the upper chamber of the hot molding fixture and then compressed and melted. The fluid mixture is transferred into a molding cavity surrounding the rotor core in the lower chamber and cooled. After cooling, the finished permanent magnet rotor is ejected. Advantageously, by this method, the proportion of magnetic material to plastic may be increased to approximately 80%/20% magnetic material to plastic by volume, and the magnets may be made thinner.

Abstract: An instrumentation apparatus with curable internal magnets is shown. The apparatus comprises a magnetic rotor and a rotatably mountable spindle to which the magnetic rotor is attached. A support structure to which the spindle is rotatably mounted defines at least one retaining area. A material is poured into and cured in the retaining area, and then charged to form a magnet. The molded and cured magnet provides a constant magnetic field that acts upon the magnetic rotor, providing a return-to-zero function or a volt gauge function for the instrumentation apparatus.

Abstract: A method of manufacturing an electromagnetic device having regions of ferromagnetic material and permanent magnet material is disclosed. The electromagnetic assemblies of this invention utilize thermoplastic encapsulated iron powders and epoxy resin encapsulated permanent magnet powder. A motor frame and permanent magnet assembly is formed in a first example, while a permanent rotor assembly is formed in a second. The motor frame and permanent magnet assembly has a ferromagnetic frame defined by a region of encapsulated iron powder and an annular array of permanent magnets defined by a region of encapsulated permanent magnet material. The permanent magnet rotor assembly has a ferromagnetic core defined by a region of encapsulated iron powder and a permanent magnet shell defined by a region of encapsulated permanent magnet material.

Abstract: A mass of ferromagnetic particles moldable into stable, high strength, magnetic cores useful in thermally and chemically hostile environments comprising an iron core and a continuous layer of polyetherimide, polyethersulfone or polyamideimide spray coated onto the surface of each particle. A method of preheating and molding the particles is disclosed.

Abstract: A process for producing a rare earth-iron-boron magnet, which includes the steps of: (1) charging a melt spun powder of a rare earth-iron-boron magnet into at least one cavity, which is confined by a pair of electrodes inserted into a hole of an electrically non-conductive ceramic die; (2) subjecting the melt spun powder to a non-equilibrium plasma treatment, under a reduced atmosphere of 10.sup.-1 to 10.sup.-3 Torr, while applying a uniaxial pressure of 200 to 500 kgf/cm.sup.2 to the melt spun powder in the direction connecting the electrodes interposed between a pair of thermally insulating members, thereby fusing the melt spun powder; and (3) heating the fused melt spun powder to a temperature higher than or equal to its crystallization temperature by transferring a Joule's heat generated in the thermally insulating members by passing a current through the members to the melt spun powder thereby causing the plastic deformation of the melt spun powder to form a rare earth-iron-boron magnet.

Abstract: A process for producing resin bonded magnet structures is disclosed which includes the steps of: (a) adding a solid epoxy resin of at least one epoxy oligomer and a microcapsule which contains at least one liquid epoxy resin to a melt spun powder of a rare earth element-iron alloy to form a granulated intermediate material, wherein the epoxy oligomer has alcoholic hydroxyl groups in the molecular chain thereof and the solid epoxy resin has a softening temperature (Durran's melting point) of 65.degree. C. to 85.degree. C.; (b) mixing the granulated intermediate material with a powdered curing agent and a lubricant to form a compound; (c) forming a green body of a resin bonded magnet by compressing the compound, and then integrating the green body directly with a supporting member; and (d) curing the solid and liquid epoxy resins in the green body by application of heat to form a rigid structure of the resin bonded magnet integrated with the supporting member.

Abstract: The process for preparing a multi-polar anisotropic resinous magnet by preparing a multi-polar anisotropic resinous magnet by injecting a liquid reaction curable resin containing a magnetic powder into a mold for molding and applying a magnetic field for multiple-pole orientation thereon; the reaction curable resin is injected into a mold for molding set between a large number of magnetic poles arranged at predetermined intervals including magnetic poles with freely convertible magnetism and back yokes opposed to these magnetic poles; a magnetic flux flows in one direction to the back yokes with the respective magnetic poles being made the same polarity, maintaining the resin under uncured state, to localize and orient the magnetic powder in the resin corresponding to the magnetic flux.

Abstract: A method of forming a cylindrical compact for a cylindrical magnet is improved by moving a core pin and a die of a mold at the same time of pressing magnet materials with a pressing punch in the same direction as that of the pressing punch at travelling speed Vc and Vd indicated by following equation:Vc=m.multidot.Vp(0.5.ltoreq.m.ltoreq.1.0)Vd=n.multidot.Vp(0.5.ltoreq.n.ltoreq.1.0)where Vc is the travelling speed of the core pin, Vd is the travelling speed of the die and Vp is the pressing speed of the pressing punch. It is possible to form the thin-walled elongated cylindrical compact by utilizing the frictional force caused between the mold and the magnet materials for forming the compact very effectively in order to obtain a thin walled elongated cylindrical magnet.

Abstract: An improved process for forming high quality ferrite magnets utilizes relatively coarsely ground magnetic materials. The process includes pre-milling a blended and calcined magnetic material to about 0.7-1.2 microns, pressing the blend into a preform shape in the presence of an orienting magnetic field, granulating the preformed material, pre-sintering the granules short of complete sintering, milling the granules to a coarse size of about 1-2 microns, forming the milled blend into desired forms in the presence of an orienting magnetic field, sintering the pressed material, and optionally machining the sintered material.

Abstract: An apparatus for magnetizing a permanent magnet which includes a frame including first and second relatively movable members arranged to form a core frame which supports first and second conic co-axial poles enclosed by the movable frame members for creating a magnetic flux circuit with an adjustable air gap for enclosing a product to be magnetized. The apparatus is energized by coils wound about the poles and enclosing the air gap. The poles include a bore co-axially aligned with the co-axial axis of the poles and a press ram dimensioned to move within the bore.

Abstract: A hollow cylindrical flux source (HCFS) is formed into a toroidal shape. A hollow toroidal of magnetically neutral material is mounted in the central cavity of the toroidal flux source. The hollow toroidal has a central coaxial toroidal cavity of given cross-section (e.g., rectangular). The toroid flux source and the hollow toroid are each equatorially split into two halves. When the two halves are brought into juxtaposition and a suspension of magnetic material is deposited in the coaxial toroidal cavity a permanent magnet toroidal ring will be fabricated.

Abstract: Methods of doubly coating iron particles. The methods comprise treating the iron particles with phosphoric acid to form a layer of hydrated iron phosphate at the surfaces of the iron particles. The particles are heated in an inert atmosphere at a temperature and for a time sufficient to convert the hydrated layer to an iron phosphate layer. The particles are then coated with a termoplastic material to provide a coating of thermoplastic material substantially uniformly circumferentially surrounding the iron phosphate layer. Doubly-coated iron particles provided in accordance with this invention are generally useful for forming magnetic components and cores for use in high frequency switching applications.

Abstract: Disclosed is a magnet which is composed mainly of magnetic powders expressed by R-T-B (R is Nd or that partially replaced with rare earth elements and T is Fe or that partially replaced with transition metal.) and a chelate resin or a chelate resin in admixture with other synthetic resins. The magnetic has markedly improved resistance to deterioration caused by oxidation and corrosion.

Abstract: An iron ore or mill scale is crushed to form a powder having an average particle diameter not exceeding 12 microns. The powder is heated at a temperature of 600.degree. C. to 900.degree. C. in the presence of oxygen to form an iron oxide containing at least 98.0% of Fe.sub.2 O.sub.3. The iron oxide is mixed with strontium oxide or carbonate. The mixture is calcined to form strontium ferrite. The calcined product is pulverized, the crushed material is molded in a magnetic field, and the molded product is sintered to yield a magnet of strontium ferrite having a high level of performance.

Abstract: Anisotropic rare-earth permanent magnets characterized in that an aggregate of a plurality of blocks, to each of which anisotropy is imparted, is formed using powders of magnetic material containing rare-earth elements, and the adjoining blocks are powder-metallurgically bonded together under pressure into one piece; a method of making anisotropic rare-earth permanent magnets by molding anisotropic blocks by magnetic-field molding, arranging, aggregating and sealing a plurality of blocks in a bag, and cold hydrostatic pressing the aggregate of blocks in the absence of magnetic field; and a suitable metal mold for magnetic-field molding anisotropic permanent magnets of a relatively large size.

Abstract: Disclosed is a device for manufacturing Nd-Fe-B alloy magnet materials, and in particular, for manufacturing an integral, columnar-ring-shaped Nd-Fe-B magnet which is multi-pole-magnetized along the circumference thereof and which is used as the rotor magnet of a high-efficiency stepping motor. The device of this invention is composed of a die punch, an upper and a lower punch having two concentric sections. The space is defined by the die and the upper and lower punches includes induction means for heating the green compact or the densified compact and sealing means for keeping the die under a reduced pressure condition or in an inert gas atmosphere.

Abstract: A method for producing a resin-bonded magnet, which includes steps of mixing a magnet element and microcapsules each of which contains at least one component of a thermally polymerizable resin composition as a binder component, mechanically breaking at least a part of the microcapsules during formation of a green compact comprising said resin composition and said magnet element to discharge the components of said resin composition from the capsules, and curing said resin to produce the resin-bonded magnet.

Abstract: A method of concurrently compacting and bonding a plurality of solid particles together including combining particles with a thermobonding agent, placing the particle-agent combination in a die having a desired shape, and applying compaction pressure to the particles while concurrently applying sufficient ultrasonic energy to the particles to densify the particles and thermally activate the thermobonding agent.

Abstract: Composite magnetic compacts having good conductivity and excellent mechanical and magnetic properties and their forming methods. The composite magnetic compacts are basically made by forming mixtures consisting essentially of 1 to 50 percent by weight of a magnetic powder and the remaining percentage of a powder of superplastic Zn-22A1 alloy. A drop in the strength of the compacts that occurs when the mixing percentage of the magnetic powder increases is made up for by the impregration of plastic in the compacts or the simpler addition of a plastic power to the mixture of the powders of magnetic material and superplastic Zn-22A1 alloy. The forming methods of the composite magnetic compacts are carried out at different temperatures and under different conditions depending on the composition of the powder mixtures and so on.

Abstract: Production of a bonded magnet from a composition of a cross-linkable organic material and a particulate magnetic material by(1) placing in a mold a shaped composition in which the particles of magnetic material are optionally aligned and demagnetized,(2) rotating the mold about an axis thereof,(3) cross-linking the organic material in the shaped composition while rotating the mold,(4) recovering from the mold a shaped article, and(5) optionally remagnetizing the particles.

Abstract: A method for producing a noncircular magnet having asymmetric magnetic properties along axes thereof. A particle charge of composition from which the magnet is to be produced is placed in a container, heated and extruded within the container to compact the particle charge to substantially full density. The particle charge may include at least one rare earth element. The particle charge may be extruded through a noncircular extrusion die, specifically a rectangular die.

Abstract: Procedure for the production of magnetic plastic laminate in which at least one of the paper fiber sheets impregnated with phenolic and melaminic resins, is first of all spread, using the silk screen process, with a cloth with a weave of from 9 to 24 threads per cm.sup.2, with a ferrous powder based paste with a percentage comprised of between 55%-80% and a binder with a percentage comprised of between 45%-20%; after drying the percentage of ferrous powders is comprised of between 75%-80%, the thickness of the paste of between 0.5 and 2.0 mm and the plastic laminate thus obtained is permanently magnetized through an electric charge thanks to the presence of the ferrous powders inside it.

Abstract: A die head is disclosed for use on an extruder die in which a plate-like structure having an elongated slot through which extrudate is extruded. the slot has a central area which is narrower than the height at each end of the elongated slot. The elongated slot also is arcute in shape, and the central area to each end portion is a mirror image of one another. The die head produces an extrudate which is uniform in thickness throughout a cross-section taken normal to the direction of extrusion, but the extrudate is bowed or arcuate in shape. The combination of a metallic shell and a flexible arcuate magnetic material is also disclosed in which the extruded flexible magnetic strip material is curled within the cylindrical shell such that both the peripheral exterior surface and the peripheral interior surface of the flexible magnetic material is flat in axial cross-section.

Abstract: There is provided a soft magnetic material composition comprising 70 to 95 vol % of soft magnetic material powder, with the balance being a liquid thermosetting resin. The composition has a high density and initial permeability. According to the process of this invention, the composition can be efficiently made into molded products of high permeability having a high strength and dimensional accuracy.

Abstract: A method of making a bonded permanent magnet including the steps of dissolving, in a solvent, an uncured epoxy resin having an incorporated catalyst which is inactive at a temperature of about 120.degree. F. Particles of a rapidly quenched rare earth-iron-boron alloy are added to the epoxy resin solution. The solution with the particles are mixed at a temperature of about 120.degree. F. until the solvent is removed and the magnetic particles are substantially uniformly coated with the resin. The epoxy coated particles are then cold-pressed into a compact to form a magnet and the epoxy compact is then cured by heating.

Abstract: A method of forming a 360.degree. ceramic permanent magnet by utilizing a hot isostatic pressing technique on a ceramic preform paterial cylindrically formed and placed inside a deformable metal housing having an inner diameter that is approximately the same but only slightly larger than the outer diameter of the preform. A solid steel mandrel is provided in the center diameter of the hollow cylindrical preform. Crystal alignment and densification of the ceramic material is achieved by using the hot isostatic pressing technique applied to the outside of the housing, preform and mandrel assembly.

Abstract: Disclosed is a method of manufacturing an electromagnetic member having properties of magnetic anisotropy as well as electrical conductivity, comprising the steps of coating an outer circumferential surface of each of a plurality of magnetic strips with a first electrically conductive material to a predetermined thickness to thereby form a plurality of composite magnetic strips, binding the plurality of composite magnetic strips, and filling spaces among the plurality of composite magnetic strips in the bundle with a second electrically conductive material substantially the same as the first electrically conductive material. By this method, a mechanically strong electromagnetic member can be obtained in which adjusting the thickness of the first electrically conductive material, the ratio between the magnetic property and the electrically conductive property can be easily adjusted by adjusting the thickness of the first electrically conductive material and blow-holes can be prevented from being generated.

Abstract: A process for the preparation of a ferrite magnetic particulate for magnetic recording which comprises steps of: (1) melting a starting material mixture containing a basic component for hexagonal ferrite, a coercive force-reducing component and a glass-forming component; (2) rapidly cooling the resulting molten mixture to obtain an amorphous material; (3) heat-treating said amorphous material to form ferrite crystals; and (4) removing components other than the ferrite crystals from the material resulting from said heat-treatment:characterized in that a step for pulverizing said amorphous material and/or a step of pulverizing said heat-treated amorphous material are included in advance of the above step (4).

Abstract: Permanent magnet materials of the Fe-B-R type are produced by:preparing a metallic powder having a mean particle size of 0.3-80 microns and a composition of 8-30 at % R, 2-28 at % B, and the balance Fe,compacting, andsintering, at a temperature of 900-1200 degrees C. Co up to 50 at % may be present. Additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) may be present. The process is applicable for anisotropic and isotropic magnet materials.

Abstract: A method of producing a permanent magnet in which a material containing ferromagnetic powder is molded into a columnar or cylindrical molded body through injection molding, compression molding, or the like, in a magnetic field capable of orienting and magnetizing the ferromagnetic powder. The method comprises the steps of applying a magnetic field to the molded body in the unidirection perpendicular to an axis of rotation of the molded body to orient and magnetize the molded body so as to have two magnetic poles of N and S; demagnetizing the magnetized molded body; and divisionally remagnetizing the demagnetized molded body on its outer or inner surface to form at least two stripes of N and S poles arranged alternately and extending parallel to the axis of rotation of the molded body.

Abstract: A plastic magnet injection molding machine comprises a stationary platen side and a movable platen side block each made of a ferromagnetic material and fixed to or integrated with a stationary and a movable platen, a stationary platen side and a movable platen side exciting coil arranged at the outer circumferences of respective ferromagnetic blocks, and a stationary platen side and a movable platen side cover each made of a non-magnetic material and attached to respective platens so as to surround the outer circumferences of the respective exciting coil and ferromagnetic block. The stationary platen side ferromagnetic block and non-magnetic cover have, respectively, surfaces each being in opposition to the movable platen and being flush with each other in a single plane parallel with the stationary platen.

Abstract: Method for making magnetic rolls having a plurality of magnets integrally set fast with a retaining member at stated portions of the periphery of a roll shaft thereby forming a magnetic force generating part, in which the retaining member is made from a rigid synthetic resin or resin foam, and optionally having a strain absorbing groove at a portion outside of said magnetic force generating part are provided.

Abstract: Apparatus and method for forming radial orientation rare earth-transition metal magnets in continuous arc rings by hot isostatic pressing. A method includes the steps of compacting rare earth-transition metal powders having a particle size up to 40 microns into radially oriented rings in a mold provided with a radially aligning field, stacking a plurality of compacted radially oriented rings within an annular cavity within a sealed, evacuated canister to form a cylinder of a predetermined height, subjecting the canister to temperatures in the range of 900.degree. to 1150.degree. C. under a gas pressure of 15 kpsi to densify the compacts, and cooling the canister and the compacts to room temperature.

Abstract: A method of preparing an elastically deformable magnetic object in which fine metal particles treated with a settable organic substance are mixed with a rubber material in a pulverized form to make a powdery mass. This is shaped under pressure, in a magnetic field into a compacted body and heated followed by cooling to allow the powder particles of rubber materials to bond to the magnetic particles and join them together to yield a homogeneous elastically deformable metal object with the magnetic particles uniformly distributed therein.

Abstract: A cylindrical permanent magnet suitable for use as the rotor magnet of a stepping motor. The magnet is a sintered cylindrical permanent magnet having a composition expressed by MO.nFe.sub.2 O.sub.3, where M represents Ba, Sr, Pb or mixture thereof, while n represents a value of 5 to 6. The sintered cylindrical permanent magnet is provided on its surface with multipolar anisotropy of more than 8 (eight) magnetic poles. Disclosed also is a method of producing the cylindrical permanent magnet.

Abstract: A cylindrical permanent magnet suitable for use as the rotor magnet of a stepping motor. The magnet is a sintered cylindrical permanent magnet having a composition expressed by MO.nFe.sub.2 O.sub.3, where M represents Ba, Sr, Pb or mixture thereof, while n represents a value of 5 to 6. The sintered cylindrical permanent magnet is provided on its surface with multipolar anisotropy of more than 8 (eight) magnetic poles. Disclosed also is a method of producing the cylindrical permanent magnet.