Available Samarium Cobalt Magnet Grades

Samarium Cobalt Magnetic and Physical Characteristics

Many grades of Samarium Cobalt magnets exist to support a variety of industrial applications.  The range of SmCo Magnet grades typically extends from 16 MGOe to 32 MGOe.  This range allows for optimizing cost, performance, and operational temperature resistance.
There are two main types of Samarium Cobalt magnet alloy.  The older version, typically denoted as (1-5) having one Samarium atom per 5 Cobalt atoms, and the newer Samarium Cobalt magnet alloy, typically denoted as (2-17), having an atomic ratio of two Samarium atoms to 14 – 17 Cobalt atoms.  (The 14 – 17 atoms are actually comprised of a mix of transition metals, Cobalt, Copper, and Iron, where Cobalt is the most abundant.)

Samarium Cobalt (1-5):

Has an Energy Product range of 15 – 24 MGOe and can typically operate up to 250°C.  By weight this alloy will be compromised of approximately 35% Samarium and the balance being Cobalt.  Typically the more recent (2-17) Samarium Cobalt magnet alloy will be selected for new applications because of the higher Energy Densities and temperature operating points; however, the older alloy is specified on many drawings originating from the late 1970’s through the late 1990’s and oftentimes it cannot be substituted.

Samarium Cobalt (1-5) Dura
Magnet
GradeResidual
Induction
BrCoercive
Force
HcIntrinsic
Coercive
Force
HciMaximum
Energy
Product
(BH)maxMax.
Working
Temp.* RangeRangeMinimumRange k-GaussTeslak-OerstedkA/mk-OerstedkA/mMGOekJ/m3 SC-16157.7-8.6
0.77-0.86
7.7-8.3
613-664
15
1,194
15-18
120-143
250°C / 482°F SC-18198.3-8.9
0.83-0.89
8.0-8.6
640-688
19
1,520
17-19
136-152
250°C / 482°F SC-20198.7-9.3
0.87-0.93
8.3-8.9
664-712
19
1,520
19-21
136-168
250°C / 482°F SC-22199.2-9.8
0.92-0.98
8.6-9.4
688-755
161,280
21-23
168-184
250°C / 482°F SC-24169.7-10.3
0.97-1.03
9.1-9.9
728-792
161,280
23-25
184-200
250°C / 482°F *The effective Maximum Operating Temperature for a Samarium Cobalt Magnet is a function of the magnet’s magnetic characteristics and the geometry of the system (the magnet and the circuit). The listing maximum operating temperature is a recommendation and infers and ideal geometry and no external demagnetizing fields. Please engage Dura to review the application before selecting a particular grade.

Samarium Cobalt (2-17):

Has an Energy Product range of 21 – 32 MGOe and typically operates up to 300°C to 350°C.  By weight, this alloy will be comprised of approximately 25% Samarium and the remainder being the Transition Metal blend comprised mostly of Cobalt.  The higher Energy Density and operating temperatures allows this magnet alloy to be a favorite choice of designers when magnetic and environmental performance is paramount.

Samarium Cobalt (2-17) Dura
Magnet
GradeResidual
Induction BrCoercive
Force
HcIntrinsic
Coercive
Force
HciMaximum
Energy
Product
(BH)maxMax.
Working
Temp.* RangeRangeMinimumRange k-GaussTeslak-OerstedkA/mk-OerstedkA/mMGOekJ/m3 SC-22289.4-10.00.94-1.09.0-9.8720-784282,240
21-23168-184
350°C / 662°F SC-242810.0-10.61.0-1.069.2-10.0736-800282,24023-25192-208350°C / 662°F SC-261810.5-10.91.03-1.09
9.3-10.3
744-82418
1,44025-27
200-216300°C / 572°F SC-282610.7-11.31.07-1.139.4-10.6
752-848
262,08027 - 29216-232300°C / 572°F SC-301811.0-11.61.10-1.16
8.9-10.1
712-808
181,440
29-31
232-248
300°C / 572°F SC-321511.2-11.81.12-1.188.9-10.1712-808151,20030-32248-256300°C / 572°F *The effective Maximum Operating Temperature for a Samarium Cobalt Magnet is a function of the magnet’s magnetic characteristics and the geometry of the system (the magnet and the circuit). The listing maximum operating temperature is a recommendation and infers and ideal geometry and no external demagnetizing fields. Please engage Dura to review the application before selecting a particular grade.
Reversible Temperature Coefficient for Br (α) Temperature Range
(°C)Induction Br (α) SmCo 1-5
(%)/°C

Induction Br (α) SmCo 2-17
(%)/°C

-100°C to 20°C
-0.045%
-0.030%
20°C to 100°C
-0.045%
-0.030%
100°C to 200°C
-0.050%
-0.035%
α = Δ Br / Δ T * 100 (Br @ 20°C) [ΔT = Relevant ranges listed above.]
Samarium Cobalt Magnets - Physical Properties PropertyUnitsValues SmCo (1-5)Values SmCo (2-17) Vickers HardnessHv450 - 500500 - 600 Densityg/cm38.38.4 Curie Temp TC°C700 - 750800 - 850 Curie Temp TF°F1,292 - 1,3821,472 - 1,562 Specific ResistanceμΩ⋅cm5386 Bending StrengthN/m21.8 x 1081.5 x 108 Compressive StrengthN/m210 x 1088 x 108 Thermal Expansion Parallel (∥) to Orientation (M)°C-16 x 10-68 x 10-6 Thermal Expansion Perpendicular (⊥) to Orientation (M)°C-113 x 10-611 x 10-6 Young's ModulusN/m21.6 x 10111.2 x 1011 Tensile StrengthN/m24 x 1073.5 x 107
The listed values are approximate and should be used as a reference.  Any magnetic or physical characteristics should be substantiated before selecting a
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The listed values are approximate and should be used as a reference. Any magnetic or physical characteristics should be substantiated before selecting a magnet material . Please engage Dura’s magnet Design / Development team members before selecting a design path.