NdFeB Magnets
| Item | Parameters | Reference Value |
| Mechanical and physical properties | Density(g/cm3) | 7.45~7.70 |
| Vickers Hardness(Hv) | 650 | |
| Electrical Resistivity(μΩ•m) | 1.4 | |
| Compressive Strength(MPa) | 1050 | |
| Tensile Strength(MPa) | 80 | |
| Bending Strength(MPa) | 290 | |
| Thermal Conductivity(W/(m•K)) | 6~8 | |
| Young's Modulus(GPa) | 160 | |
| Coefficient of Thermal Expansion(C ⊥) | -1.5 | |
| Coefficient of Thermal Expansion(C //) | 6.5 | |
| Additional magnetic properties | Temp.Coeff.ofBr (α(Br))/(%/K) | -0.08~-0.12 |
| Temp.Coeff.of Hcj (β(Hcj))/(%/K) | -0.42~-0.70 | |
| Curie Temperature (Tc)/(°C) | 310~380 | |
| Recoil Permeability (μrec)/(-) | 1.05 |
NdFeB Magnetic Properties
| Properties | Remanence | Coercive force | Intrinsic coercive force | Maximum energy product | Working temp | |||||||||||
| Unit | kGs | T | kOe | kA/m | MGOe | kJ/m3 | ||||||||||
| Nom. | Min. | Nom. | Min. | Nom. | Min. | Nom. | Min. | Nom. | Min. | Nom. | Min. | |||||
| No | Grade | kOe | kA/m | ℃ | ||||||||||||
| 1 | N30 | 11.2 | 10.8 | 1.12 | 1.08 | 10.5 | 10 | 836 | 796 | ≥12 | ≥955 | 30 | 28 | 239 | 223 | ≤80 |
| 2 | N35 | 12 | 11.7 | 1.2 | 1.17 | 11.3 | 10.8 | 900 | 860 | ≥12 | ≥955 | 35 | 33 | 279 | 263 | ≤80 |
| 3 | N38 | 12.6 | 12.2 | 1.26 | 1.22 | 11.5 | 11.3 | 915 | 900 | ≥12 | ≥955 | 38 | 36 | 303 | 287 | ≤80 |
| 4 | N40 | 12.9 | 12.6 | 1.29 | 1.26 | 11.6 | 11.4 | 924 | 908 | ≥12 | ≥955 | 40 | 38 | 318 | 303 | ≤80 |
| 5 | N42 | 13.1 | 12.9 | 1.31 | 1.29 | 11.8 | 11.5 | 939 | 915 | ≥12 | ≥955 | 42 | 40 | 342 | 326 | ≤80 |
| 6 | N45 | 13.6 | 13.3 | 1.36 | 1.33 | 12 | 11.6 | 955 | 924 | ≥12 | ≥955 | 45 | 43 | 358 | 342 | ≤80 |
| 7 | N48 | 14 | 13.8 | 1.4 | 1.38 | 10.8 | 10.2 | 860 | 810 | ≥11 | ≥875 | 48 | 46 | 383 | 367 | ≤80 |
| 8 | N50 | 14.3 | 14.1 | 1.43 | 1.41 | 10.8 | 10 | 860 | 794 | ≥11 | ≥875 | 50 | 48 | 398 | 383 | ≤80 |
| 9 | N52 | 14.5 | 14.2 | 1.45 | 1.42 | 10.8 | 10 | 860 | 794 | ≥11 | ≥875 | 52 | 50 | 414 | 398 | ≤60 |
| 10 | N54 | 15.1 | 14.5 | 1.51 | 1.45 | 10.5 | 10 | 836 | 794 | ≥11 | ≥875 | 54 | 51 | 429 | 406 | ≤60 |
| 11 | N55 | 15.4 | 14.7 | 1.54 | 1.47 | 10.5 | 10 | 836 | 794 | ≥11 | ≥875 | 55 | 52 | 438 | 414 | ≤60 |
| 12 | N30M | 11.2 | 10.8 | 1.12 | 1.08 | 10.5 | 10 | 836 | 794 | ≥14 | ≥1114 | 30 | 28 | 239 | 223 | ≤100 |
| 13 | N35M | 12 | 11.7 | 1.2 | 1.17 | 11.3 | 10.9 | 900 | 868 | ≥14 | ≥1114 | 35 | 33 | 279 | 263 | ≤100 |
| 14 | N38M | 12.6 | 12.2 | 1.26 | 1.22 | 11.8 | 11.3 | 939 | 900 | ≥14 | ≥1114 | 38 | 36 | 303 | 287 | ≤100 |
| 15 | N40M | 12.9 | 12.6 | 1.29 | 1.26 | 12 | 11.6 | 955 | 924 | ≥14 | ≥1114 | 40 | 38 | 318 | 303 | ≤100 |
| 16 | N42M | 13.2 | 12.9 | 1.32 | 1.29 | 12.4 | 12 | 987 | 955 | ≥14 | ≥1114 | 42 | 40 | 342 | 326 | ≤100 |
| 17 | N45M | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥14 | ≥1114 | 45 | 43 | 358 | 342 | ≤100 |
| 18 | N48M | 14 | 13.8 | 1.4 | 1.38 | 13.3 | 12.9 | 1059 | 1027 | ≥14 | ≥1114 | 48 | 46 | 383 | 367 | ≤100 |
| 19 | N50M | 14.3 | 14 | 1.43 | 1.4 | 13.5 | 13.1 | 1074 | 1042 | ≥14 | ≥1114 | 50 | 48 | 398 | 383 | ≤100 |
| 20 | N52M | 14.5 | 14.2 | 1.45 | 1.42 | 13.6 | 13.2 | 1082 | 1050 | ≥14 | ≥1114 | 52 | 50 | 414 | 398 | ≤80 |
| 21 | N30H | 11.2 | 10.8 | 1.12 | 1.08 | 10.5 | 10 | 836 | 794 | ≥17 | ≥1353 | 30 | 28 | 239 | 223 | ≤120 |
| 22 | N33H | 11.7 | 11.4 | 1.17 | 1.14 | 11 | 10.5 | 876 | 836 | ≥17 | ≥1353 | 33 | 31 | 263 | 247 | ≤120 |
| 23 | N35H | 12 | 11.7 | 1.2 | 1.17 | 11.3 | 10.9 | 900 | 868 | ≥17 | ≥1353 | 35 | 33 | 279 | 263 | ≤120 |
| 24 | N38H | 12.6 | 12.2 | 1.26 | 1.22 | 11.8 | 11.3 | 939 | 900 | ≥17 | ≥1353 | 38 | 36 | 303 | 287 | ≤120 |
| 25 | N40H | 12.8 | 12.6 | 1.28 | 1.26 | 12 | 11.6 | 955 | 924 | ≥17 | ≥1353 | 40 | 38 | 318 | 303 | ≤120 |
| 26 | N42H | 13 | 12.8 | 1.3 | 1.28 | 12.4 | 12 | 987 | 955 | ≥17 | ≥1353 | 42 | 40 | 342 | 326 | ≤120 |
| 27 | N45H | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥17 | ≥1353 | 45 | 43 | 358 | 342 | ≤120 |
| 28 | N48H | 14 | 13.8 | 1.4 | 1.38 | 13.3 | 12.9 | 1059 | 1027 | ≥17 | ≥1353 | 48 | 46 | 383 | 367 | ≤120 |
| 29 | N50H | 14.3 | 14 | 1.43 | 1.4 | 13.5 | 13.1 | 1074 | 1042 | ≥17 | ≥1353 | 50 | 48 | 398 | 383 | ≤120 |
| 30 | N52H | 14.5 | 14.2 | 1.45 | 1.42 | 13.6 | 13.2 | 1082 | 1050 | ≥17 | ≥1353 | 52 | 50 | 414 | 398 | ≤100 |
| 31 | N30SH | 11.2 | 10.8 | 1.12 | 1.08 | 10.5 | 10.1 | 836 | 804 | ≥20 | ≥1595 | 30 | 28 | 239 | 223 | ≤150 |
| 32 | N33SH | 11.7 | 11.4 | 1.17 | 1.14 | 11 | 10.6 | 876 | 844 | ≥20 | ≥1595 | 33 | 31 | 263 | 247 | ≤150 |
| 33 | N35SH | 12 | 11.7 | 1.2 | 1.17 | 11.3 | 11 | 900 | 876 | ≥20 | ≥1595 | 35 | 33 | 279 | 263 | ≤150 |
| 34 | N37SH | 12.3 | 12 | 1.23 | 1.2 | 11.5 | 11.3 | 915 | 900 | ≥20 | ≥1595 | 37 | 35 | 295 | 279 | ≤150 |
| 35 | N38SH | 12.5 | 12.2 | 1.25 | 1.22 | 11.8 | 11.4 | 939 | 908 | ≥20 | ≥1595 | 38 | 36 | 303 | 287 | ≤150 |
| 36 | N40SH | 12.7 | 12.5 | 1.27 | 1.25 | 12.1 | 11.8 | 963 | 939 | ≥20 | ≥1595 | 40 | 38 | 318 | 303 | ≤150 |
| 37 | N42SH | 13 | 12.8 | 1.3 | 1.28 | 12.4 | 12 | 987 | 955 | ≥20 | ≥1595 | 42 | 40 | 342 | 326 | ≤150 |
| 38 | N45SH | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥20 | ≥1595 | 45 | 43 | 358 | 342 | ≤150 |
| 39 | N48SH | 14 | 13.8 | 1.4 | 1.38 | 13.3 | 12.9 | 1059 | 1027 | ≥20 | ≥1595 | 48 | 46 | 383 | 367 | ≤130 |
| 40 | N50SH | 14.2 | 14 | 1.42 | 1.4 | 13.5 | 13.1 | 1074 | 1042 | ≥20 | ≥1595 | 50 | 48 | 398 | 383 | ≤130 |
| 41 | N25UH | 10 | 9.6 | 1 | 0.96 | 9.6 | 9.2 | 764 | 732 | ≥25 | ≥1990 | 25 | 22 | 199 | 175 | ≤180 |
| 42 | N28UH | 10.8 | 10.4 | 1.08 | 1.04 | 10.2 | 9.8 | 812 | 780 | ≥25 | ≥1990 | 28 | 26 | 223 | 207 | ≤180 |
| 43 | N30UH | 11.2 | 10.8 | 1.12 | 1.08 | 10.6 | 10.1 | 844 | 804 | ≥25 | ≥1990 | 30 | 28 | 239 | 223 | ≤180 |
| 44 | N33UH | 11.5 | 11.3 | 1.15 | 1.13 | 11 | 10.6 | 876 | 844 | ≥25 | ≥1990 | 33 | 31 | 263 | 247 | ≤180 |
| 45 | N35UH | 11.9 | 11.7 | 1.19 | 1.17 | 11.3 | 11 | 900 | 876 | ≥25 | ≥1990 | 35 | 33 | 279 | 263 | ≤180 |
| 46 | N38UH | 12.5 | 12.2 | 1.25 | 1.22 | 11.8 | 11.4 | 939 | 908 | ≥25 | ≥1990 | 38 | 36 | 303 | 287 | ≤180 |
| 47 | N40UH | 12.7 | 12.5 | 1.27 | 1.25 | 12.2 | 11.8 | 971 | 939 | ≥25 | ≥1990 | 40 | 38 | 318 | 303 | ≤180 |
| 48 | N42UH | 13 | 12.8 | 1.3 | 1.28 | 12.4 | 12 | 987 | 955 | ≥25 | ≥1990 | 42 | 40 | 342 | 326 | ≤180 |
| 49 | N45UH | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥25 | ≥1990 | 45 | 43 | 358 | 342 | ≤150 |
| 50 | N48UH | 14 | 13.8 | 1.4 | 1.38 | 13.3 | 12.9 | 1059 | 1027 | ≥25 | ≥1990 | 48 | 45 | 383 | 367 | ≤150 |
| 51 | N50UH | 14.2 | 13.9 | 1.42 | 1.39 | 13.5 | 13.1 | 1074 | 1042 | ≥24 | ≥1911 | 50 | 48 | 398 | 383 | ≤150 |
| 52 | N28EH | 10.8 | 10.4 | 1.08 | 1.04 | 10.4 | 9.8 | 811 | 780 | ≥30 | ≥2388 | 28 | 26 | 223 | 207 | ≤200 |
| 53 | N30EH | 11.2 | 10.8 | 1.12 | 1.08 | 10.6 | 10.1 | 844 | 804 | ≥30 | ≥2388 | 30 | 28 | 239 | 223 | ≤200 |
| 54 | N33EH | 11.5 | 11.3 | 1.15 | 1.13 | 11 | 10.6 | 876 | 844 | ≥30 | ≥2388 | 33 | 31 | 263 | 247 | ≤200 |
| 55 | N35EH | 11.9 | 11.7 | 1.19 | 1.17 | 11.3 | 11 | 900 | 876 | ≥30 | ≥2388 | 35 | 33 | 279 | 263 | ≤200 |
| 56 | N38EH | 12.4 | 12.2 | 1.24 | 1.22 | 11.8 | 11.4 | 939 | 908 | ≥30 | ≥2388 | 38 | 36 | 303 | 287 | ≤200 |
| 57 | N40EH | 12.7 | 12.4 | 1.27 | 1.24 | 12.2 | 11.8 | 971 | 939 | ≥30 | ≥2388 | 40 | 38 | 318 | 303 | ≤200 |
| 58 | N42EH | 13 | 12.8 | 1.3 | 1.28 | 12.4 | 12 | 987 | 955 | ≥30 | ≥2388 | 42 | 40 | 334 | 318 | ≤200 |
| 59 | N45EH | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥30 | ≥2388 | 45 | 43 | 358 | 342 | ≤200 |
| 60 | N48EH | 14 | 13.8 | 1.38 | 1.38 | 13.3 | 12.9 | 1059 | 1027 | ≥30 | ≥2388 | 48 | 46 | 383 | 367 | ≤200 |
| 61 | N28AH | 10.8 | 10.4 | 1.08 | 1.04 | 10.4 | 9.8 | 811 | 780 | ≥33 | ≥2626 | 28 | 26 | 223 | 207 | ≤220 |
| 62 | N30AH | 11.2 | 10.8 | 1.12 | 1.08 | 10.6 | 10.1 | 844 | 804 | ≥33 | ≥2626 | 30 | 28 | 239 | 223 | ≤220 |
| 63 | N33AH | 11.5 | 11.3 | 1.15 | 1.13 | 11 | 10.6 | 876 | 844 | ≥33 | ≥2626 | 33 | 31 | 263 | 247 | ≤220 |
| 64 | N35AH | 11.9 | 11.7 | 1.19 | 1.17 | 11.5 | 11 | 915 | 876 | ≥33 | ≥2626 | 35 | 33 | 279 | 263 | ≤220 |
| 65 | N38AH | 12.4 | 12.2 | 1.24 | 1.22 | 11.8 | 11.4 | 939 | 908 | ≥33 | ≥2626 | 37 | 35 | 294 | 279 | ≤220 |
| 66 | N40AH | 12.7 | 12.4 | 1.27 | 1.24 | 12.1 | 11.8 | 971 | 939 | ≥33 | ≥2626 | 39 | 37 | 310 | 294 | ≤220 |
| 67 | N42AH | 13 | 12.8 | 1.3 | 1.28 | 12.4 | 12 | 987 | 955 | ≥33 | ≥2626 | 42 | 40 | 334 | 318 | ≤220 |
| 68 | N45AH | 13.5 | 13.3 | 1.35 | 1.33 | 12.6 | 12.2 | 1003 | 971 | ≥33 | ≥2626 | 45 | 43 | 358 | 342 | ≤220 |
| 69 | N28TH | 10.8 | 10.4 | 1.08 | 1.04 | 10.4 | 9.8 | 811 | 780 | ≥40 | ≥3185 | 28 | 26 | 223 | 207 | ≤240 |
| 70 | N30TH | 11.2 | 10.8 | 1.12 | 1.08 | 10.6 | 10.1 | 844 | 804 | ≥40 | ≥3185 | 30 | 28 | 239 | 223 | ≤240 |
| 71 | N33TH | 11.5 | 11.3 | 1.15 | 1.13 | 11 | 10.6 | 876 | 844 | ≥40 | ≥3185 | 33 | 31 | 263 | 247 | ≤240 |
| 72 | N35TH | 11.9 | 11.7 | 1.19 | 1.17 | 11.5 | 11 | 915 | 876 | ≥40 | ≥3185 | 35 | 33 | 279 | 263 | ≤240 |
| 73 | N38TH | 12.4 | 12.2 | 1.24 | 1.22 | 11.8 | 11.4 | 939 | 908 | ≥40 | ≥3185 | 37 | 35 | 294 | 279 | ≤240 |
| 74 | N40TH | 12.7 | 12.4 | 1.27 | 1.24 | 12.1 | 11.8 | 971 | 939 | ≥40 | ≥3185 | 39 | 37 | 310 | 294 | ≤240 |
| 75 | N28RH | 10.8 | 10.4 | 1.08 | 1.04 | 10.4 | 9.8 | 811 | 780 | ≥45 | ≥3583 | 28 | 26 | 223 | 207 | ≤260 |
| 76 | N30RH | 11.2 | 10.8 | 1.12 | 1.08 | 10.6 | 10.1 | 844 | 804 | ≥45 | ≥3583 | 30 | 28 | 239 | 223 | ≤260 |
| 77 | N33RH | 11.5 | 11.3 | 1.15 | 1.13 | 11 | 10.6 | 876 | 844 | ≥45 | ≥3583 | 33 | 31 | 263 | 247 | ≤260 |
| 78 | N35RH | 11.9 | 11.7 | 1.19 | 1.17 | 11.5 | 11 | 915 | 876 | ≥45 | ≥3583 | 35 | 33 | 279 | 263 | ≤260 |
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Industry Application
Answers to Frequently Asked Questions
Core Performance Indicators for NdFeB Magnet Grades in Motor Applications
Motor-oriented NdFeB magnets focus on three key indicators, which are the core basis for grade division and selection:
- Intrinsic Coercivity (Hcj): Represents the magnet’s resistance to demagnetization; higher values ensure stable magnetism in high-temperature, reverse magnetic field environments, avoiding motor performance degradation.
- Maximum Energy Product (BHmax): Determines the magnetic field strength; high-energy-product grades enable motors to achieve higher power with smaller size and lighter weight, improving power density.
- Temperature Stability (Curie Temperature/Tw): Defines the maximum safe operating temperature; matching the motor’s actual working temperature is the core to prevent thermal demagnetization failure.
Classification of High-Performance NdFeB Magnet Grades for Motors
High-performance NdFeB magnets for motors are divided into standard high-energy, high-coercivity, and ultra-high-temperature resistant grades according to application scenarios, covering all types of motor working conditions:
1. Standard High-Energy NdFeB Grades (Low-Temperature, High-Efficiency Motors)
Suitable for motors working at 60℃–100℃, with high energy product and cost-effective advantages, mainly used in small household appliances, low-power tools, and conventional drive motors:
- N35–N52: Basic high-energy grades, N52 has the highest room-temperature energy product, ideal for small motors pursuing compact size; limited to low-temperature and low-load scenarios, poor high-temperature resistance.
2. High-Temperature Resistant NdFeB Grades (Medium-Temperature Industrial Motors)
Modified by adding cobalt, terbium, and other elements, with improved temperature resistance, suitable for motors working at 100℃–180℃, covering most industrial, automotive, and commercial motors:
- M Grade (100℃): N35M–N50M, balanced energy and coercivity, for hydraulic motors, fan motors, and small industrial drive motors;
- H Grade (120℃): N35H–N50H, universal high-temperature grade, widely used in air-conditioning compressors, electric tool motors, and automotive fuel pumps;
- SH Grade (150℃): N35SH–N48SH, high coercivity, stable performance at medium high temperature, for new energy vehicle wipers, industrial frequency conversion motors, and pump motors;
- UH Grade (180℃): N30UH–N45UH, ultra-high coercivity, resists high-temperature demagnetization, for high-temperature fans, packaging machinery motors, and automotive transmission motors.
3. Ultra-High-Temperature Resistant NdFeB Grades (Extreme High-Temperature High-Performance Motors)
Heavy rare earth optimized grades, suitable for motors working at 200℃–230℃ extreme environments, exclusive to high-end high-power motors:
- EH Grade (200℃): N28EH–N40EH, for new energy vehicle main drive motors, high-power servo motors, and aerospace servo motors;
- TH Grade (230℃): N25TH–N35TH, top high-temperature grade, for military motors, oil drilling motors, and high-temperature industrial furnace drive motors.
Grade Matching Guide for Different Motor Types (Core Application Solutions)
Targeted grade selection for mainstream motor types to directly solve user selection pain points:
- New Energy Vehicle (NEV) Main Drive Motors: Priority EH/TH grade (N35EH, N30TH), high temperature resistance + high energy product, ensuring 10-year service life under high-speed and high-load conditions;
- Industrial Servo Motors: SH/UH grade (N40SH, N35UH), high precision and high coercivity, adapting to frequent forward/reverse rotation and strong reverse magnetic fields;
- HVAC Compressor Motors: H/SH grade (N45H, N40SH), energy-saving and high-temperature resistant, matching long-term continuous operation;
- Electric Tool Motors: M/H grade (N48M, N45H), high magnetic strength and impact resistance, adapting to high-speed vibration working conditions;
- Aerospace/High-Temperature Industrial Motors: TH grade, ultra-high temperature stability and reliability, meeting extreme environment requirements.
Key Selection Principles to Avoid Motor Failure
- 1. Temperature first: Select the grade with temperature level 20℃–30℃ higher than the motor’s actual maximum working temperature;
- 2. Load matching: High-load/high-reverse magnetic field motors must choose high-coercivity grades (SH/UH/EH) to avoid demagnetization;
- 3. Volume constraint: Small-sized high-power motors use high-energy-product grades (N45–N52 series) to improve power density;
- 4. Service life: Long-term continuous working motors give priority to high-coercivity grades, reducing aging and demagnetization risks.
Why High-Performance NdFeB Magnets Are Irreplaceable for Motors
Compared with Alnico, ferrite, and other magnets, high-performance NdFeB magnets have unparalleled advantages in motor applications:
- Higher magnetic energy product, reducing motor volume and weight by 30%–50%;
- Excellent coercivity, stable performance in high-temperature and complex magnetic fields;
- Improve motor energy efficiency level by 5%–15%, reducing energy consumption and operating costs;
- Customizable grades and sizes, fully adapting to various high-performance motor designs.
Conclusion
The selection of high-performance NdFeB magnet grades for motor applications needs to comprehensively match the motor’s working temperature, load characteristics, volume requirements, and service life. Standard grades (N/M/H) are suitable for conventional motors, medium high-temperature grades (SH/UH) for industrial/automotive motors, and ultra-high-temperature grades (EH/TH) for high-end extreme motors. Correct grade selection is the core to improve motor efficiency, extend service life, and reduce failure rates. For customized high-performance motor magnetic solutions, professional magnet manufacturers can provide targeted grade optimization and design support.