Power Conversion (PC) Iron Powders

General Material Properties

Material Reference
Permeability		 Powder Type Temp Coef of Perm
(+ppm/C°)		 Density
gm/cm³		 Max Frequency
(MHz)		 Relative Cost Color Code
Toroid
-2 10 Carbonyl Iron 95 5 45 2.1 Red/Clear
-8 35 Carbonyl Iron 255 6.5 5.0 2.8 Yellow/Red
-14 14 Iron 150 5.2 20 3.0 Black/Red
​-18​ 55 Iron 385 6.6 1.3 3.2 Green/Red
-19 55 Iron 650 6.8 1.0 1.0 Red/Green
-26 75 Iron 825 7.0 0.38 1.0 Yellow/White
-30 22 Iron 510 6.0 1.8 1.2 Green/Gray
-34 33 Iron 565 6.2 1.4 1.3 Gray/Blue
-35 33 Iron 665 6.3 1.1 1.2 Yellow/Gray
-38 85 Iron 956 7.1 0.27 1.1 Gray/Black
-40 60 Iron 950 6.9 0.38 1.0 Green/Yellow
-45 100 Iron 1043 7.2 0.34 3.2 Black/Black
-52 75 Iron 650 7.0 0.59 1.1 Green/Blue

 

 

Material Magnetic Characteristics

Material Bsat (G) H (Oe) at
80% μi		 %μi at
H=50 (Oe)		 μ effective at
H=50 (Oe)

Cores Loss (mW/cm³)

60 Hz/5000 G 10 kHz/500 G 100 kHz/140 G 1 MHz/40 G 10 MHz/15 G
-2 14,800 673 99 10 19 32 18 9 27
-8 17,600 101 92 32 45 59 32 22 123
-14 15,200 406 99 14 19 32 18 11 49
-18 17,800 45 77 42 48 70 46 70 715
-19 18,200 48 79 43 31 72 54 99 1138
-26 18,500 25 55 41 32 75 83 327 4294
-30 16,700 120 93 20 37 120 129 248 2537
-34 17,100 78 89 29 29 87 82 157 1756
-35 17,300 76 88 29 33 109 119 241 2531
-38 18,700 23 51 44 31 72 103 532 7216
-40 18,400 33 67 40 29 93 127 530 6999
-45 18,900 18 43 43 26 60 61 212 2716
-52 18,500 30 62 46 30 68 58 134 1571
  • ‐2 & ‐14 Materials: The low permeability of these materials will result in lower operating AC flux density than other materials with no additional gap‐loss. The ‐14 Material is similar to ‐2 Material with a higher permeability.
  • ‐8 Material: This material has low core loss and good linearity under high bias conditions. A good high frequency material, also the highest cost iron powder material.
  • ‐18 Material: This material has low core loss similar to the ‐8 Material with higher permeability and a lower cost. Good DC saturation characteristics.
  • ‐19 Material:  An inexpensive alternate to the ‐18 Material with the same permeability and somewhat higher core losses.
  • ‐26 Material: A very popular material, it is a cost‐effective general purpose material that is useful in a wide variety of power conversion and line filter applications.
  • ‐30 Material: The good linearity, low cost and relatively low permeability of this material make a popular choice for high power UPS applications.
  • ‐34, ‐35 Materials: An inexpensive alternate to the ‐8 Material where high frequency core loss is not critical. Both ‐34 & ‐35 Materials have good linearity with high bias.
  • ‐38 Material: Similar to the ‐26 Material with higher permeability.
  • ‐40 Material: The least expensive iron powder material, characteristics similar to the ‐26 Material with a lower permeability. Most popular is large sizes.
  • ‐45 Material: The highest permeability iron powder material available. Consider as a high perm alternate to the ‐52 Material with slightly higher core losses.
  • ‐52 Material: This material has lower core losses at high frequency and the same permeability as the ‐26 Material. It is popular for high frequency choke designs and available in a wide variety of geometries.

 

Initial Permeability (µi) vs. DC
Magnetizing Force

Percent Initial Permeability (%µi) vs.
DC Magnetizing Force

Percent Initial Permeability (%µi) vs. Peak AC
Flux Density

Initial Permeability (µi) vs Frequency (Hz)

BH Curves

Material Frequency Range