High-Performance Sintered NdFeB Magnets

Custom grades, precision machining, stable magnetic consistency and engineering support—from first sample to repeat production.

View Material Selection Guide →

PRODUCT FORMS

Standard Shapes. Drawing-Based Solutions.

Choose a common geometry or send a drawing for machining and magnetization review.

Nickel-coated sintered NdFeB disc magnets

Disc MagnetsAxial or diametrical magnetization

Nickel-coated sintered NdFeB block magnets

Block MagnetsGround faces, chamfers and slots

Nickel-coated sintered NdFeB ring magnets

Ring MagnetsAxial, diametrical or multipole

Sintered NdFeB arc magnets for motors and rotors

Arc MagnetsMotor and rotor applications

Countersunk MagnetsAssembly-ready geometry

Segment MagnetsMatched sets and polarity control

Custom-shaped sintered NdFeB magnets manufactured to drawing

Custom ShapesDrawing-based machining review

Laminated NdFeB magnet for reduced eddy-current loss

Laminated MagnetReduced eddy-current loss for high-speed motors

Engineering advantage

Why Engineering Teams Choose Guande

We connect material selection, manufacturability review and process control so a drawing can move from first sample to stable repeat production with fewer technical risks.

Typical ±0.05 mm

Precision Tolerances

Ground dimensions, parallelism and critical geometry are reviewed against shape, size, brittleness and the selected inspection method.

6+ surface systems

Application-Matched Coatings

Ni-Cu-Ni, zinc, epoxy, phosphating, passivation and special systems are selected around humidity, corrosion, bonding and assembly needs.

DFM before scale-up

Fast Sampling & DFM Support

Drawing review, magnetization planning and prototype validation help confirm the design and production specification before volume release.

Tolerance, coating and sampling targets are confirmed against the final geometry, application environment and inspection agreement.

Material data centre

Technical Specifications & Material Grades

Compare reference magnetic properties, then review temperature, coating, tolerance and magnetization requirements with our engineering team before final grade selection.

Grade	Br (kGs)	Br (Tesla)	Hcj (kOe)	Hcj (kA/m)	Hcb (kOe)	Hcb (kA/m)	(BH)max (MGOe)	(BH)max (kJ/m3)	Density ρ (g/cm3)	Curie Temp Tc (℃)	Max Temp Tw (℃)	Rec Permeability μrec
N35	11.7~12.2	1.17~1.22	12	955	10.9	867	33~36	263~287	7.45	310	80	1.05
N38	12.2~12.5	1.22~1.25	12	955	11.3	899	36~39	287~310	7.5	320	80	1.05
N40	12.5~12.8	1.25~1.28	12	955	11.6	923	38~41	302~326	7.5	320	80	1.05
N42	12.8~13.2	1.28~1.32	12	955	11.6	923	40~43	318~342	7.5	320	80	1.05
N45	13.2~13.6	1.32~1.36	12	955	11	875	43~46	342~366	7.5	320	80	1.05
N48	13.6~14.0	1.36~1.40	12	955	11.2	891	46~49	366~390	7.5	320	80	1.05
N50	14.0~14.3	1.40~1.43	12	955	10.5	836	47~51	374~406	7.55	320	80	1.05
N52	14.3~14.6	1.43~1.46	12	955	10.5	836	51~53	390~422	7.55	320	80	1.05
N35M	11.7~12.2	1.17~1.22	14	1114	10.9	867	33~36	263~287	7.5	320	100	1.05
N38M	12.2~12.5	1.22~1.25	14	1114	11.3	899	36~39	287~310	7.5	320	100	1.05
N40M	12.5~12.8	1.25~1.28	14	1114	11.6	923	38~41	302~326	7.5	320	100	1.05
N42M	12.8~13.2	1.28~1.32	14	1114	12	955	40~43	318~342	7.5	320	100	1.05
N45M	13.2~13.6	1.32~1.36	14	1114	12.5	995	43~46	342~366	7.5	320	100	1.05
N48M	13.6~14.0	1.36~1.40	14	1114	12.8	1019	46~49	366~390	7.55	320	100	1.05
N50M	14.0~14.3	1.40~1.43	14	1114	13	1035	47~51	374~406	7.55	320	100	1.05
N52M	14.3~14.6	1.43~1.46	14	1114	12.5	995	51~53	390~422	7.55	320	100	1.05
N35H	11.7~12.2	1.17~1.22	17	1353	10.9	867	33~36	263~287	7.5	320	120	1.05
N38H	12.2~12.5	1.22~1.25	17	1353	11.3	899	36~39	287~310	7.5	320	120	1.05
N40H	12.5~12.8	1.25~1.28	17	1353	11.6	923	38~41	302~326	7.5	320	120	1.05
N42H	12.8~13.2	1.28~1.32	17	1353	12	955	40~43	318~342	7.55	320	120	1.05
N45H	13.2~13.6	1.32~1.36	17	1353	12.2	971	43~46	342~366	7.55	320	120	1.05
N48H	13.6~14.0	1.36~1.40	17	1353	12.9	1027	46~49	358~390	7.6	320	120	1.05
N50H	14.0~14.3	1.40~1.43	16	1273	13	1035	47~51	374~406	7.6	320	120	1.05
N35SH	11.7~12.2	1.17~1.22	20	1592	11	875	33~36	263~287	7.55	320	150	1.05
N38SH	12.2~12.5	1.22~1.25	20	1592	11.4	907	36~39	287~310	7.55	320	150	1.05
N40SH	12.5~12.8	1.25~1.28	20	1592	11.8	939	38~41	302~326	7.55	320	150	1.05
N42SH	12.8~13.2	1.28~1.32	20	1592	12.2	971	40~43	318~342	7.55	320	150	1.05
N45SH	13.2~13.6	1.32~1.36	20	1592	12.3	979	43~46	342~366	7.6	320	150	1.05
N48SH	13.6~14.0	1.36~1.40	19	1512	12.5	995	46~49	366~390	7.6	320	150	1.05
N35UH	11.7~12.2	1.17~1.22	25	1989	10.8	859	33~36	263~287	7.6	320	180	1.05
N38UH	12.2~12.5	1.22~1.25	25	1989	11	875	36~39	287~310	7.6	320	180	1.05
N40UH	12.5~12.8	1.25~1.28	25	1989	11.5	915	38~41	302~326	7.6	320	180	1.05
N42UH	12.8~13.2	1.28~1.32	25	1989	12.2	971	40~43	310~342	7.6	320	180	1.05
N45UH	13.2~13.6	1.32~1.36	24	1909	12.3	979	43~46	342~366	7.6	320	180	1.05
N35EH	11.7~12.2	1.17~1.22	30	2387	10.5	836	33~36	263~287	7.6	320	200	1.05
N38EH	12.2~12.5	1.22~1.25	30	2387	11.5	915	36~39	279~310	7.6	320	200	1.05
N33EH	11.3~11.7	1.13~1.17	34	2706	10.3	820	31~34	239~271	7.6	320	240	1.05
N35AH	11.7~12.2	1.17~1.22	34	2706	10.5	836	33~36	255~287	7.6	320	240	1.05

Engineering selection reference: Published values are comparative starting points at approximately 20°C. Final grade, coating, tolerances and magnetization must be checked against geometry, the magnetic working point, thermal cycle, environment, production volume and the agreed inspection method.

Thermal selection

Operating Temperature

Grade suffix indicates increasing intrinsic coercivity and a higher reference operating-temperature class. The chart is a selection guide—not a guaranteed continuous-use curve.

0°C4080120160200240°C

80°C

100°C

120°C

150°C

180°C

200°C

230°C

Design check: magnet thickness, permeance coefficient/load line, opposing field and acceptable irreversible loss can reduce the usable temperature. Confirm with the demagnetization curve and application geometry.

Surface protection

Coating Options

Coating selection balances dimensional build, corrosion exposure, handling and the intended bonding process. Edge coverage and surface preparation are as important as nominal film thickness.

Coating system	Typical total build	Comparative corrosion test*	Bonding / assembly interface	Typical use
Ni-Cu-Ni	15–21 μm	Up to 24 h	Hard, smooth surface; cleaning and surface activation may be required for structural adhesive bonding.	General indoor industrial use, appearance and wear resistance.
Ni-Cu + black epoxy	20–28 μm	Up to 48 h	Verify adhesive compatibility and cure temperature; control edge damage during assembly.	Humidity, splash exposure and improved electrical insulation.
Zinc	7–15 μm	Up to 12 h	Generally bondable after cleaning; lower hardness than nickel systems.	Cost-sensitive indoor products and moderate protection.
Phosphate / passivation	Process-specific	Interim protection; validate by specification	Useful as a conversion/pre-treatment surface; adhesion must be qualified with the selected adhesive.	Bonded assemblies, process holding and applications with secondary encapsulation.

* Comparative reference for common published systems, typically tested at 35°C with 5% NaCl. Results vary with supplier process, geometry, edge coverage and acceptance criteria. Specify the required test method and hours on the drawing or quality agreement.

Grinding & DFM

Tolerance & Machining

Sintered NdFeB is brittle and is normally finished by diamond grinding. Keep geometry simple and place tight tolerances only on functional dimensions.

Disc / CylinderOD, thickness, flatness

BlockLength, width, thickness, squareness

RingOD, ID, wall, concentricity

Arc SegmentRadius, angle, width, radial thickness

Shape	Functional dimensions	Typical quotation starting point	Machining / inspection note
Disc / cylinder	OD and thickness	±0.05 mm	Add flatness/parallelism only where the air gap or bonding stack requires it.
Ring	OD, ID and thickness	±0.05 mm	Thin walls, tight concentricity and small IDs increase breakage and grinding risk.
Block	Length, width and thickness	±0.05 mm	Chamfers and edge breaks reduce chipping; define datum and squareness when functional.
Arc segment	Radius, radial thickness and width	±0.05 mm; angle typically ±0.5°	Rotor-stack fit is often controlled by chord, parallelism, matched-set and polarity checks.

Drawing rule: these are practical starting points for ground parts, not automatic acceptance limits. Dimensions tighter than approximately 0.025 mm (0.001 in), complex slots, very thin walls or geometric tolerances require a dedicated DFM and inspection review.

Pole configuration

Magnetization Direction

The preferred orientation is created during pressing, so magnetization direction must be defined before tooling and blank layout are fixed. Multipole patterns require dedicated fixtures and feasibility review.

Disc — axialN/S on opposite flat faces

Block — through thicknessLength or width direction available by review

Ring — axialN/S on opposite annular faces

Ring — radialInner/outer poles; geometry and tooling limited

Arc segments: standard pressed-block arcs commonly use a parallel/diametric magnetization vector. True radial arcs, radial rings and axial/radial multipole patterns need dedicated pressing orientation and magnetizing fixtures; submit pole count, pole pitch and reference face with the drawing.

Scale-up strategy

Maximum Size

There is no single universal maximum dimension for sintered NdFeB. Feasibility is governed by the combined blank, grinding, coating, handling and magnetizing envelope.

Geometry & aspect ratioThin walls, large unsupported spans and sharp transitions raise fracture risk.

Pressing orientationThe preferred magnetic axis must fit the available press and blank route.

Grinding & coatingLarge faces and edges require stable fixturing, thickness control and complete coverage.

Magnetizing fixtureEnergy and fixture aperture can be the limiting step after machining.

Single piece or segmented assembly?For large rings, rotor arcs and high-energy blocks, a matched multi-piece design often improves manufacturability, magnetic consistency and replacement control.Review drawing + annual volume

Quality planning

Inspection Standard

Inspection is built around the drawing and functional risk. Define the magnetic measurement method, fixture, reference surface and sampling plan before sample approval.

01 · FAI / SampleDrawing review, critical dimensions, appearance and magnetic baseline.

02 · Process ControlMaterial lot, grinding, coating thickness and polarity controls.

03 · Functional CheckSurface field, flux, magnetic moment or pull force with agreed fixture.

04 · Release RecordsInspection report, CoC and traceability package as specified.

Dimensions & GD&TAppearance / chipsCoating thicknessPolarity & directionFlux / moment / fieldPull force by fixtureFAI / PPAP-style recordsRoHS / REACH support

Demagnetization curves, raw-material certificates, sampling reports and special reliability tests are available by agreement. Acceptance limits must identify the instrument, air gap, fixture and temperature where applicable.

INDUSTRY APPLICATIONS

Magnet Selection That Starts With the Application

We translate operating conditions into a manufacturable grade, coating, geometry and inspection plan.

Motors & DrivesTorque density, thermal stability and arc matching

Sensors & EncodersField repeatability, position accuracy and compact size

Medical EquipmentClean surfaces, traceability and controlled magnetic output

Industrial AutomationCycle life, reliable sensing and stable supply

Consumer ElectronicsThin geometries, cosmetic coatings and volume consistency

Renewable EnergyHigh-coercivity grades and long-term operating reliability

Controlled from powder to performance

Manufacturing Capability & Quality Control

A connected production route protects magnetic performance, dimensional consistency and traceability from material preparation through final shipment.

01
Material & Powder Control

Alloy chemistry, oxygen exposure and particle distribution are controlled for stable magnetic properties.
02
Orientation & Pressing

Magnetic alignment and compact density are managed to achieve the intended easy-axis direction.
03
Sintering & Heat Treatment

Temperature, time and atmosphere are tuned to develop density, coercivity and batch consistency.
04
Precision Machining

Grinding, slicing and wire cutting deliver controlled profiles, parallelism and critical dimensions.
05
Coating & Magnetization

Surface protection and magnetization fixtures are matched to the environment and magnetic circuit.
06
Final Inspection & Traceability

Dimensional, visual and magnetic checks are linked to lot records and shipment documentation.

Dimensional Verification

CMM, optical inspection and calibrated gauges verify critical dimensions, geometry and tolerances.

Magnetic Performance

Material properties and finished-part flux, surface field or magnetic moment are checked to the agreed plan.

Reliability & Coating

Appearance, adhesion and application-specific corrosion or environmental tests protect service life.

FAQ

Common Technical Questions

Practical answers for engineering and procurement teams.

How do I choose the right NdFeB grade?

Choose the grade from the required flux or force, operating temperature, magnet geometry and magnetic circuit—not from remanence alone. Share the drawing and working conditions, and we will compare practical grade options and cost.

How does temperature affect NdFeB magnets?

Temperature reduces coercivity and can cause irreversible flux loss if the working point is too low. Select N, M, H, SH, UH, EH or AH only after reviewing peak temperature, duration and the magnetic circuit.

What coating should I choose?

Ni-Cu-Ni suits many indoor applications. Zinc can be a cost-effective option, while epoxy is preferred when moisture or corrosion risk is higher. Bonding, salt spray and appearance requirements should be reviewed together.

What information is needed for a quotation?

Send the drawing, target force or flux, magnetization direction, operating temperature, environment, inspection requirements, annual volume and expected sample timing. We can then return a practical quotation and technical questions quickly.

Sintered NdFeB Magnets