How To Order Magnetics Powder Cores

Magnetics powder cores have unique part numbers that provide important information about the characteristics of the cores. A description of part type is provided below.

Toroids

toroid2.jpg

1. Grading Code

  • C0 = Graded into 2% inductance bands – OD <5 mm, 5% bands 
  • 00 = Not graded

2. Material Code

  • 55 = MPP 
  • 58 = High Flux 
  • 77 = Kool Mμ 
  • 78 = XFLUX
  • 79 = Kool Mμ® MAX
  • 75 = 75-Series

3. Catalog Number

  • Designates size and permeability 

4. Core Finish Code

Core Finish Voltage Breakdown Material Availability OD Size Availability Permeability Availability
A2 1,000 volts min MPP, High Flux All All
A7 1,000 volts min Kool Mµ, XFlux, 75 Series, Kool Mμ MAX All All
AY 600 volts min All 3.56 - 16.5 mm 14µ - 300µ
A5 2,000 volts min All >4.65 mm All
A9 8,000 volts min All >4.65 mm All
W4 1,000 volts min MPP >4.65 mm 60µ - 200µ
M4 1,000 volts min MPP >4.65 mm 60µ - 200µ
  • No voltage breakdown min for A2 or A7 with OD≤4.65 mm

Powder Core (Toroid) Stamping Summary

Size        (O.D. mm) 6-digit
Shop Order Number
2-digit
Material Code
3-digit
Catalog Number
2-digit
Core Finish Code
Inductance
Code
Inductance
Example 
6.35-6.86
    123456 020 +6
7.87-12.7    123456 050A2 +6
>12.7  123456 55120A2 +6
  • Inductance Code is only stamped on MPP toroids with C0- Grading Code.
  • Shop Order number identifies the product batch, ensuring traceability of every core through the entire manufacturing process, back to raw materials.
  • Cores with O.D. less than 6.35 mm are not stamped.

Powder Core (Toroid) Stamping Examples

PowderCoreStamping.JPG

E CORES, LARGE E CORES, SEGMENTS and THINZ

  E-core.jpg large-E-core1.jpg
1 Grading Code 00 = Not graded 00 = Not graded
2 Material Code

M = MPP 
H = High Flux 
K = Kool Mµ 
X = XFlux

M = MPP 
H = High Flux 
K = Kool Mµ 
X = XFlux
3 Size Code First two digits equal length in mm
Last two digits equal height in mm
Length in mm 
4 Shape Code E = E Core 
T = Toroid 
U = U core 
P = I Core/Plate 
B = Blocks
LE = Large E Core 
TC = Toroid 
RT = Race Track 
IS = I Segment 
AR = Arc Segment 
5 Permeability Code 014 for 14µ
026 for 26µ
040 for 40µ
060 for 60µ
090 for 90µ 
014 for 14µ
026 for 26µ
040 for 40µ
060 for 60µ
090 for 90µ

E Cores Stamping Examples:

KME4020E040.jpg