Rectangular NdFeB Magnets

Description

Product Overview

Rectangular NdFeB magnets are the most critical component in internal permanent magnet (IPM) electric motors. Produced from sintered neodymium-iron-boron powder through isostatic pressing and vacuum sintering, they combine the highest energy density of any commercial permanent magnet material with tight dimensional tolerance for reliable motor assembly.

Ningbo Vanguard Technologies supplies block magnets across the full grade family — from standard N-grade through M, H, SH, UH, and EH high-temperature series — enabling precise performance matching for each motor operating environment. All pieces undergo full magnetic testing, dimensional inspection, and salt-spray or HAST corrosion evaluation before shipment.

Whether you need a standard catalogue geometry or a fully custom block profile, Vanguard can provide sample shipment within 10–15 days and mass-production support for rotor assembly or bare-magnet supply.

Quick View

Rectangular NdFeB Magnet Selection Snapshot

N35-N55

Available Grade Range

From high Br standard grades to high-coercivity motor grades.

80-200 °C

Working Temperature Range

N, M, H, SH, UH and EH series can be selected by thermal margin.

0.05 mm

Tight Tolerance Option

Precision grinding supports rotor slot fitting and automated assembly.

10-15 Days

Prototype Sample Lead Time

Fast sampling after drawing, grade, coating and magnetization confirmation.

Temperature Grade Guide

N Series

80 °C

M Series

100 °C

H Series

120 °C

SH Series

150 °C

UH / EH

180-200 °C

Application Demand Focus

EV Traction

High Hcj

Linear Motor

Uniformity

Robot Joint

Compact

Aerospace

Stability

Electronics

Small Size

1Drawing ReviewL, W, T, chamfer, tolerance

2Grade MatchBr, Hcj, thermal margin

3Coating PlanNiCuNi, epoxy, Zn, custom

4MagnetizationThickness, length, width direction

5InspectionFlux, size, coating, appearance

Industries Served

Key Applications

EV Traction Motors

Drive motors for BEV/PHEV requiring SH/UH-grade rectangular magnets with ≥150 °C Tw for sustained high-speed operation.

Linear motors

High-precision rectangular magnets for linear servo motors and actuators; uniform magnetic field distribution supports smooth motion in automation, 3D printing, and precision positioning stages.

Consumer electronics motors

Miniature rectangular magnets for compact BLDC motors in smart devices, cooling fans, camera modules and laptop assemblies, with stable magnetic output for low-noise operation.

Aerospace & Defense

High-coercivity block magnets for aerospace actuators, navigation modules and satellite attitude-control motors requiring lightweight design and high-temperature stability.

Robot Joint Motors

Compact high-torque rectangular magnets for humanoid robot and AGV joint actuators with tight dimensional tolerances.

Energy Storage Systems

Rectangular magnets for energy storage converter motors, cooling fans and magnetic sensors, supporting stable output under long-term cyclic operation.

Magnetic Performance

Grade & Magnetic Properties

Standard grades for rectangular NdFeB magnets. All values at 20 °C. Values are typical; exact grade selection is confirmed per application.

Grade	Remanence		Coercivity		Intrinsic Coercivity		Max. Energy Product		Temp. Coefficient (α)		Max. Working Temperature °C (L/D=0.7)
	Br		Hcb		Hcj		(BH)max		αBr (%/°C)	αHcj (%/°C)
	T	kGs	kA/m	kOe	kA/m	kOe	kJ/m³	MGOe	αBr (%/°C)	αHcj (%/°C)
N30	1.08–1.13	10.8–11.3	≥798	≥10.0	≥955	≥12	223–247	28–31	−0.12	−0.76	80
N33	1.13–1.17	11.3–11.7	≥836	≥10.5	≥955	≥12	247–271	31–34	−0.12	−0.76	80
N35	1.17–1.22	11.7–12.2	≥868	≥10.9	≥955	≥12	263–287	33–36	−0.12	−0.76	80
N38	1.22–1.25	12.2–12.5	≥899	≥11.3	≥955	≥12	287–310	36–39	−0.12	−0.76	80
N40	1.25–1.28	12.5–12.8	≥907	≥11.4	≥955	≥12	302–326	38–41	−0.12	−0.76	80
N42	1.28–1.32	12.8–13.2	≥915	≥11.5	≥955	≥12	318–342	40–43	−0.12	−0.76	80
N45	1.32–1.38	13.2–13.8	≥923	≥11.6	≥955	≥12	342–366	43–46	−0.12	−0.76	80
N48	1.38–1.42	13.8–14.2	≥923	≥11.6	≥955	≥12	366–390	46–49	−0.12	−0.76	80
N50	1.40–1.45	14.0–14.5	≥796	≥10.0	≥876	≥11	382–406	48–51	−0.12	−0.76	80
N52	1.43–1.48	14.3–14.8	≥796	≥10.0	≥876	≥11	398–422	50–53	−0.12	−0.76	80
N55	1.46–1.52	14.6–15.2	≥796	≥10.0	≥876	≥11	414–430	52–54	−0.12	−0.76	80
N35M	1.17–1.22	11.7–12.2	≥868	≥10.9	≥1114	≥14	263–287	33–36	−0.12	−0.68	100
N38M	1.22–1.25	12.2–12.5	≥899	≥11.3	≥1114	≥14	287–310	36–39	−0.12	−0.68	100
N40M	1.25–1.28	12.5–12.8	≥923	≥11.6	≥1114	≥14	302–326	38–41	−0.12	−0.68	100
N42M	1.28–1.32	12.8–13.2	≥955	≥12.0	≥1114	≥14	318–342	40–43	−0.12	−0.68	100
N45M	1.32–1.38	13.2–13.8	≥995	≥12.5	≥1114	≥14	342–366	43–46	−0.12	−0.68	100
N48M	1.37–1.43	13.7–14.3	≥1027	≥12.9	≥1114	≥14	366–390	46–49	−0.12	−0.68	100
N50M	1.40–1.45	14.0–14.5	≥1033	≥13.0	≥1114	≥14	382–406	48–51	−0.12	−0.68	100
N52M	1.43–1.48	14.3–14.8	≥1050	≥13.2	≥1114	≥14	398–422	50–53	−0.12	−0.68	100
N54M	1.45–1.50	14.5–15.0	≥1051	≥13.2	≥1114	≥14	414–438	52–55	−0.12	−0.68	100
N35H	1.17–1.22	11.7–12.2	≥868	≥10.9	≥1353	≥17	263–287	33–36	−0.12	−0.66	120
N38H	1.22–1.25	12.2–12.5	≥899	≥11.3	≥1353	≥17	287–310	36–39	−0.12	−0.66	120
N40H	1.25–1.28	12.5–12.8	≥923	≥11.6	≥1353	≥17	302–326	38–41	−0.12	−0.66	120
N42H	1.28–1.32	12.8–13.2	≥955	≥12.0	≥1353	≥17	318–342	40–43	−0.12	−0.66	120
N45H	1.32–1.36	13.2–13.6	≥963	≥12.1	≥1353	≥17	342–366	43–46	−0.12	−0.66	120
N48H	1.37–1.43	13.7–14.3	≥995	≥12.5	≥1353	≥17	366–390	46–49	−0.12	−0.66	120
N50H	1.40–1.45	14.0–14.5	≥1011	≥12.7	≥1353	≥17	382–406	48–51	−0.12	−0.66	120
N52H	1.43–1.48	14.3–14.8	≥1027	≥12.9	≥1353	≥17	398–422	50–53	−0.12	−0.66	120
N35SH	1.17–1.22	11.7–12.2	≥876	≥11.0	≥1592	≥20	263–287	33–36	−0.11	−0.56	150
N38SH	1.22–1.25	12.2–12.5	≥907	≥11.4	≥1592	≥20	287–310	36–39	−0.11	−0.56	150
N40SH	1.25–1.28	12.5–12.8	≥939	≥11.8	≥1592	≥20	302–326	38–41	−0.11	−0.56	150
N42SH	1.28–1.32	12.8–13.2	≥987	≥12.4	≥1592	≥20	318–342	40–43	−0.11	−0.56	150
N45SH	1.32–1.38	13.2–13.8	≥1003	≥12.6	≥1592	≥20	342–366	43–46	−0.11	−0.56	150
N48SH	1.37–1.43	13.7–14.3	≥1027	≥12.9	≥1592	≥20	366–390	46–49	−0.11	−0.56	150
N50SH	1.40–1.45	14.0–14.5	≥1003	≥12.6	≥1592	≥20	382–406	48–51	−0.11	−0.56	150
N30UH	1.08–1.13	10.8–11.3	≥812	≥10.2	≥1990	≥25	223–247	28–31	−0.10	−0.50	180
N33UH	1.13–1.17	11.3–11.7	≥852	≥10.7	≥1990	≥25	247–271	31–34	−0.10	−0.50	180
N35UH	1.17–1.22	11.7–12.2	≥860	≥10.8	≥1990	≥25	263–287	33–36	−0.10	−0.50	180
N38UH	1.22–1.25	12.2–12.5	≥876	≥11.0	≥1990	≥25	287–310	36–39	−0.10	−0.50	180
N40UH	1.25–1.28	12.5–12.8	≥899	≥11.3	≥1990	≥25	302–326	38–41	−0.10	−0.50	180
N42UH	1.28–1.32	12.8–13.2	≥899	≥11.3	≥1990	≥25	318–342	40–43	−0.10	−0.50	180
N45UH	1.32–1.36	13.2–13.6	≥908	≥11.4	≥1990	≥25	342–366	43–46	−0.10	−0.50	180
N48UH	1.37–1.43	13.7–14.3	≥908	≥11.4	≥1990	≥25	366–390	46–49	−0.10	−0.50	180
N28EH	1.04–1.08	10.4–10.8	≥780	≥9.8	≥2388	≥30	207–231	26–29	−0.10	−0.45	200
N30EH	1.08–1.13	10.8–11.3	≥812	≥10.2	≥2388	≥30	223–247	28–31	−0.10	−0.45	200
N33EH	1.13–1.17	11.3–11.7	≥836	≥10.5	≥2388	≥30	247–271	31–34	−0.10	−0.45	200
N35EH	1.17–1.22	11.7–12.2	≥876	≥11.0	≥2388	≥30	263–287	33–36	−0.10	−0.45	200
N38EH	1.22–1.25	12.2–12.5	≥899	≥11.3	≥2388	≥30	287–310	36–39	−0.10	−0.45	200
N40EH	1.25–1.28	12.5–12.8	≥899	≥11.3	≥2388	≥30	302–326	38–41	−0.10	−0.45	200
N42EH	1.28–1.32	12.8–13.2	≥899	≥11.3	≥2388	≥30	318–342	40–43	−0.10	−0.45	200
N45EH	1.32–1.36	13.2–13.6	≥899	≥11.3	≥2388	≥30	342–366	43–46	−0.10	−0.45	200
N28AH	1.04–1.08	10.4–10.8	≥787	≥9.9	≥2786	≥35	207–231	26–29	−0.10	−0.45	230
N30AH	1.08–1.13	10.8–11.3	≥819	≥10.3	≥2786	≥35	223–247	28–31	−0.10	−0.45	230
N33AH	1.13–1.17	11.3–11.7	≥843	≥10.6	≥2786	≥35	247–271	31–34	−0.10	−0.45	230
N35AH	1.17–1.22	11.7–12.2	≥876	≥11.0	≥2786	≥35	263–287	33–36	−0.10	−0.45	230
N38AH	1.22–1.25	12.2–12.5	≥899	≥11.3	≥2786	≥35	287–310	36–39	−0.10	−0.45	230

Typical Physical Properties (All Sintered NdFeB Grades)

Parameter	Unit	Reference Value	Parameter	Unit	Reference Value
Curie Temperature	°C	310 ~ 400	Thermal Conductivity	W/m·°C	8 ~ 10
Density	g/cm³	7.4 ~ 7.7	Young's Modulus	GPa	150 ~ 200
Vickers Hardness	HV	500 ~ 700	Electrical Resistivity (C∥)	μΩ·m	1.4 ~ 1.6
Recoil Permeability	—	1.02 ~ 1.08	Electrical Resistivity (C⊥)	μΩ·m	1.2 ~ 1.4
Compressive Strength	MPa	1000 ~ 1100	Coeff. of Thermal Expansion (C∥)	10⁻⁶/°C	4 ~ 9
Flexural Strength	MPa	150 ~ 400	Coeff. of Thermal Expansion (C⊥)	10⁻⁶/°C	−2 ~ 0

Magnetization Orientations Available

Surface Treatment

Coating & Plating Options

NdFeB is susceptible to oxidation without adequate surface protection. Vanguard specifies and verifies the following coating systems per IEC 60068 and ASTM B117 salt-spray standards.

Ni·Cu·Ni Triple Layer

Industry standard for clean, low-humidity environments. Bright silver finish.

Dimension Capability

Rectangular magnets are defined by length (L), width (W), and thickness (T). Standard tolerance is ± 0.05 mm on all dimensions; tight-tolerance ± 0.03 mm is available on request. Chamfered edges, countersunk holes, segmented blocks, and special magnetization directions can be customized for motor assembly.

Dimension	Minimum	Maximum	Standard Tol.
Length (L)	1 mm	200 mm	± 0.05 mm
Width (W)	1 mm	200 mm	± 0.05 mm
Thickness (T)	0.5 mm	50 mm	± 0.05 mm

Engineering Selection

How to Specify Rectangular NdFeB Magnets

Rectangular magnets are often simple in appearance, but their performance depends on the full motor or magnetic-circuit design. Vanguard reviews magnetic grade, magnetization direction, working temperature, assembly clearance, coating system and mechanical stress before recommending the final specification.

Grade selection: N-grade is suitable for room-temperature applications; M/H grades are used for motors with moderate thermal rise; SH/UH/EH grades are recommended for traction motors, high-speed rotors and compact assemblies with higher demagnetization risk.

Magnetization direction: Thickness, length or width magnetization can be supplied according to the magnetic circuit. Multi-pole, paired-pole and matched-set supply can also be arranged for linear motor and sensor applications.

Assembly reliability: Chamfer, edge radius, coating thickness, adhesive gap and rotor slot tolerance should be confirmed together to reduce chipping, coating damage and assembly variation.

Custom Capability

Available Custom Features

Item	Options	Typical Purpose
Geometry	Block, thin plate, long strip, segmented block, step block	Fit rotor slots, magnetic assemblies and compact device spaces.
Edge Treatment	Chamfer, radius, deburring, polished edge	Reduce chipping during handling, bonding and press-fit assembly.
Magnetization	Thickness, length, width, paired polarity, matched flux set	Support IPM motors, linear motors, sensors and magnetic fixtures.
Surface Protection	NiCuNi, Zn, epoxy, NiCuNi + epoxy, phosphating	Improve corrosion resistance according to humidity, salt spray and temperature.

Manufacturing Process

From Powder to Finished Block Magnet

Production starts with rare-earth alloy preparation, hydrogen decrepitation, jet milling and magnetic-field alignment. The pressed blanks are vacuum sintered, aged, sliced or ground to final size, then coated, magnetized, inspected and packed according to the approved drawing.

For motor applications, we can provide matched batches with controlled magnetic consistency, clean surface finish, edge protection and packaging designed for automated assembly lines.

Quality Assurance

Inspection & Validation

Magnetic testing: Br, Hcb, Hcj, (BH)max, surface flux, flux linkage and magnetization direction verification.

Dimensional control: Length, width, thickness, flatness, parallelism, perpendicularity, chamfer and appearance inspection.

Coating verification: Thickness, adhesion, salt spray, humidity resistance and thermal shock testing according to coating type.

Documentation: Material certificate, inspection report, RoHS/REACH declaration and lot traceability records are available for shipment release.

Request a Quote

Information Needed for Fast Quotation

To speed up engineering review, please send a 2D/3D drawing or list the key specifications below. If your project is still in the design stage, Vanguard can help compare grade, coating and magnetization options before tooling.

Length, width, thickness, tolerance, chamfer and surface finish requirement
Material grade or target Br/Hcj, plus maximum working temperature
Magnetization direction, polarity marking and required surface flux if available
Coating type, salt-spray requirement, adhesive process and operating environment
Sample quantity, annual volume, packing requirement and target delivery schedule

Support

Frequently Asked Questions

How do I choose between M, H, SH, and UH grades for my motor?

Grade selection depends on the maximum winding temperature your motor will experience. M-grade (≤100 °C) suits most industrial servo applications; H-grade (≤120 °C) is standard for EV auxiliary motors; SH (≤150 °C) and UH (≤180 °C) are specified for EV traction drives and high-ambient industrial use. We recommend providing your thermal simulation data so we can confirm the correct grade.

What is the minimum order quantity for custom rectangular magnets?

For custom geometry, samples can be arranged from as few as 50–200 pieces. Mass-production MOQ is typically 1000–10000 pieces per specification, though this is flexible depending on magnet size and grade. Contact us to discuss your project volume.

Can you supply rectangular magnets already assembled into a rotor?

Yes. Vanguard provides integrated rotor assembly services — including magnet bonding, balancing, and shaft press-fitting — as part of our Magnetic Systems product line. We can supply bare rectangular magnets or complete rotor sub-assemblies depending on your manufacturing flow.

Do you provide material certifications and test reports?

Full material certificates (chemical composition, magnetic test data, coating thickness, salt-spray results) are provided with each shipment as standard. ROHS, REACH, and conflict-mineral declarations are available on request.

What is the lead time for rectangular NdFeB magnets?

Prototype samples: 10–15 working days. Mass-production orders: 25–35 working days depending on grade, coating, and quantity. Rush sampling may be available — please inquire.

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Rectangular NdFeB Magnets

Description

Rectangular NdFeB Magnets

Rectangular NdFeB Magnet Selection Snapshot

Key Applications

Grade & Magnetic Properties

Coating & Plating Options

Dimension Capability

How to Specify Rectangular NdFeB Magnets

Available Custom Features

From Powder to Finished Block Magnet

Inspection & Validation

Information Needed for Fast Quotation

Frequently Asked Questions

Get in Touch with Us

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