Home Permanent Magnets Ltd.
Dattapada Road, Borivali East
Mumbai 400066. India
P r o d u c t s

Here is a list of most of our product line. These are the most commonly used alnico magnets in the industry and find the application as displayed. We also manufacture custom magnets as per requirements.

Applications and dimensions of typical cast magnets

Diagram 1
Measuring Instruments, Magnetic Chucks
A 20 20 24 28 30 50 60 80
B 10 18 20 13 18 15 12 15
C 10 12 10 12 10 10 5 15
Diagram 2
Tweeters, Transducers, Measuring Instruments
A 5 10 30 15 10 20 20 61 25
B 9.4 10 10 12 13 15 25 34 45
Diagram 3
Stepper Motors, Sensors, Transducers
A 30 12 22 38 76 19 8 50 52
A 20 27 30 35 50 51 66 102 120
A 6 19 8 7.2 16 35 50 80 68
Diagram 4
Energy Meters, Relays
A 19 22 22 24 26 29
B 15 14.5 12 17.5 9 18
C 10.4 7 8.5 12 11 10

Diagram 5
Magnetic Chucks
A 100 100 115
B 14 14 15
C 29 31 29
Diagram 6
Magnetic Holding V Block
A 14 58 63 92
B 18 24 23 28
C 31 33 35 39
Diagram 7
Automobile Speedometers
A 3 3.5 5 6
B 23 23 24 12
C 13.5 6 12.5 6
Diagram 8
Tacho Generator, Meggar
A 19 10 38
B 29.5 31 31
C 10 17 9.5

(Dimensions in mm)
We also manufacture as per customers requirements

Alnico Materials and their Properties

Characteristics:
Alnicos are precipitation-hardened alloys requiring special heat treatment techniques. The raw materials are cobalt, nickel, copper, aluminium and iron. Titanium, silicon, etc. are added in certain proportions. The raw materials in their purest form are melted in medium frequency induction furnaces and castings are made using conventional sand or shell moulds. The heat treatment consists of heating the alloy in furnace to well above its curie point, and holding it at that temperature for some time. This is followed by controlled cooling after which the castings are reheated and held for a long period at a temperature of about 6000C. This ageing process increases the coercive force and the energy product. Finally, the castings are ground to obtain close dimensional tolerances whenever necessary and inspected for physical and magnetic accuracy.

Cast Alnico Materials - Physical and Mechanical Properties (Nominal values)

Materials
Density
g/cm3
Hardness Rockwell
C
Curie Point
oC
Coefficient of
thermal expansion
per oC x 10
Electrical Resistivity
at 25 oC
M.CM
Specific Heat
Cal/gm oC
Alni 6.9 51 760 12 65 0.11
Coalni 7.0 52 700 12 62 0.11
Alnico II 7.2 53 810 12 60 0.11
Coalnimax Spl. 7.3 50 860 11.4 55 0.11
Coercimax 7.35 50 870 11.3 50 0.11
Coercimax Spl. 7.35 50 870 11.3 50 0.11

Cast Alnico Materials - Magnetic Properties (Nominal values)

Materials
Remnance
Br
Gauss
Coercivity
Hc
Oersted
Maximum Energy
Product (BH)
max MGOe
Working Point
Bd    Hd
G      O
Average Recoil
Permeability
Minimum
Magnetising Force
Hs Oersted
Reversible Temp
Coefficient of Br
% /oC
ISOTROPIC              
Alni 6200 - 6700 510 - 560 1.3 - 1.5 4000      350 4.3 3000 - 0.03
Coalni 6000 - 6500 580 - 630 1.3 - 1.5 4000      354 4.5 3000 - 0.03
Alnico-II 6700 - 7500 600 - 670 1.5 - 1.8 4000      400 4.9 3000 - 0.03
ANISOTROPIC              
Coalnimax Spl. 12100 - 12900 615 - 665 5.0 - 5.8 10000    550 3.5 3000 - 0.02
Coercimax 11100 - 11900 690 - 730 4.3 - 5.1 8400      560 4.0 3000 - 0.02
Coercimax Spl. 11700 - 12300 630 - 690 5.0 - 5.8 9800      550 3.7 3000 - 0.02


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