Table of Properties of NdFeB Magnets

Magnetic Properties
Physical and Thermal Properties

 

 

 

 

 

 


Magnetic Properties

Grade
Br (Gauss)
Hc (Oersteds)
Hci (Oersteds)
BHmax (MGOe)
Temp. Coefficient of Br
(%/
C)
Max. Op. Temp. (C)
Density (lbs/in3)
4SB
3,460
3,460
9,600
3
-0.10
150
0.217
B10N
6,800
5,780
10,300
10
-0.10
150
0.217
24
9,800
7,500
8,000
24
-0.12
80
0.275
24UH
10,000
9,600
41,000
24
-0.10
210
0.271
27
10,850
9,650
13,500
27
-0.12
80
0.267
27H
10,600
10,100
17,000
27
-0.11
150
0.271
28
10,800
10,100
17,000
28
-0.11
150
0.271
28UH
10,900
10,400
25,000
28
-0.09
190
0.271
30
11,400
10,400
13,500
30
-0.12
150
0.267
30H
11,200
10,700
17,000
30
-0.11
150
0.271
32SH
11,600
11,100
31,000
32
-0.10
180
0.271
35
12,300
11,300
14,000
35
-0.11
150
0.271
35SH
12,200
11,700
26,000
36
-0.10
160
0.271
38H
12,550
11,700
17,000
39
-0.10
130
0.271
39H
12,800
12,300
21,000
40
-0.10
150
0.271
40
12,900
12,400
12,000
40
-0.11
130
0.271
42
13,050
12,500
14,000
41
-0.11
120
0.271
42H
13,300
12,700
17,000
43
-0.10
120
0.271
45
13,550
11,750
11,000
44
-0.12
100
0.271
45H
13,500
12,900
15,000
45
-0.11
100
0.271
48
14,100
12,900
13,500
48
-0.12
80
0.271


Physical and Thermal Properties

Description SmCo 1-5 Alloys SmCo 2-17 Alloys NdFeB
Mechanical Properties:
Modulus of elasticy
23 x 106 psi
17 x 106 psi
22 x 106 psi
Ultimate tensile strength
6 x 103 psi
5 x 103 psi
12 x 103 psi
Density
8.2 g/cc
8.4 g/cc
7.4 g/cc
Coefficient of thermal expansion:
Perpendicular to orientation
13 x 10-6/C
11 x 10-6/C
-4.8 x 10-6/C
Parallel to orientation
6 x 10-6/C
8 x 10-6/C
3.4 x 10-6/C
Electrical resistivity
5 ohm cm
86 ohm cm
160 ohm cm
Magnetic Properties:
Curie temperature
750C
825C
310C
Reversible temperature coefficient of residual induction (-100C to + 100C)
-0.043% / C
-0.03% /C
-0.09 to -0.13% /C
Recoil permeability
1.05
1.05
1.05
Max. service temperature*
250C
300C
150C
* Maximum Service Temperature depends on permeance coefficient of magnetic circuit. Temperatures shown here are guidelines only  


 

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