Magnetic circuit
Show the working gap, steel path and opposing fields.
AlNiCo Magnets
Cast and sintered magnets for defined, repeatable output. Review the circuit, opposing fields and calibration requirements before selecting a grade.
Application review notes
AlNiCo combines useful temperature stability with specific magnetic-circuit requirements. We review alloy grade, geometry, opposing fields and calibration needs together, supporting applications where a defined and repeatable output matters.
START WITH YOUR REQUIREMENTS
Part geometry
Identify the required form, mating dimensions and support.
Calibration target
Agree the output, test fixture and acceptance conditions.
CAST FORMS
Start with the required geometry.
Share the intended pole faces, air gap and working environment to frame the application review.
Explore cast formsSINTERED OPTIONS
Compare the relevant route.
Material route, shape and magnetic-circuit requirements should be considered together.
Review design inputsMEASUREMENT
Make critical details measurable.
Discuss geometry, calibration and acceptance requirements before sample or production work.
Review an AlNiCo applicationFORMS & CONFIGURATIONS
Cast and Sintered AlNiCo Forms.
Representative product forms. Final geometry, dimensions and material are confirmed against your drawing.
Cast shapes
Complex geometry produced by the cast route
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Sintered parts
Small parts with tighter dimensional control
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Rings
Ring geometry for instrumentation
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Segments
Segment geometry for legacy magnetic circuits
Review This FormDESIGN & SELECTION
Review the Complete Magnetic Circuit.
- Pole faces
Define orientation and functional surfaces
- Magnetic circuit
Review working gap and reverse fields
- Assembly sequence
Confirm magnetization and handling plan
Select a category to see the inputs to confirm.
Review This ConfigurationSelection identifies the review scope. Materials, ratings and acceptance criteria remain subject to engineering confirmation.
A good fit when
- High-temperature sensors, gauges and instrumentation
- Applications needing stable flux across a wide temperature range
- Cast geometries or sintered small parts that suit the mechanical design
- Legacy or specialized systems where temperature behavior is more important than compactness
Check before release
- AlNiCo has lower coercivity than most rare-earth grades and needs a load-line review
- The material can be vulnerable to demagnetization from opposing fields or poor magnetic-circuit design
- Cast and sintered routes have different geometry, tolerance and surface-finish implications
- Mechanical retention and pole orientation should be designed without relying on the magnet as a structural part
ENGINEERING REVIEW
Protect the Working Point.
Assess the return path and worst opposing field alongside temperature and calibration requirements.
Temperature map
Give the magnet temperature range, gradients, cycling rate and the allowable change in flux or sensitivity.
Demagnetizing field
Provide opposing field, nearby steel, armature position and the worst-case open-circuit or fault condition.
Manufacturing route
State whether the part is cast or sintered, along with geometry, machining allowance, surface finish and appearance limits.
Calibration target
For sensors and instruments, define the output window, magnet-to-sensor distance, matching requirement and calibration method.
MATERIAL REFERENCE
Technical Data, Clearly Presented.
Complete technical grade data12 reference rows
12 rows
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Units and Notes
Calculated secondary equivalents use the published primary display values: kJ/m³ for energy product, and Oe for the AlNiCo coercivity table. The ≈ symbol indicates rounded conversion, not a new measurement. Approved supply limits and source revisions are confirmed for the project.
Notation: Br is remanent flux density; HcB (Hcb/bHc) is normal coercivity; HcJ (Hcj/Hci/iHc) is intrinsic coercivity. Grade identifiers retain their source naming. Historical aliases do not establish identical supply specifications.
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| Grade / Route | Br kG / T | Hc Oe / kA/m | Hci Oe / kA/m | (BH)max MGOe / kJ/m³ | Temperature conditions | |
|---|---|---|---|---|---|---|
| Alnico 2 (Sintered) | 7.0 kG / 0.70 T | 500 Oe / 40 kA/m | ≥540 Oe / 43 kA/m | 1.5 MGOe / 12 kJ/m³ | Confirm duty profile | Material Datasheet |
| Alnico 5 (Sintered) | 11.0 / 1.10 | 600 / 48 | ≥600 / 48 | 4.25 / 34 | Confirm duty profile | Material Datasheet |
| Alnico 8 (Sintered) | 8.8 / 0.88 | 1530 / ≈121.8 | ≥1600 / 127 | 5.25 / 42 | Confirm duty profile | Material Datasheet |
| Alnico 5 (Cast) | 12.2 / 1.22 | 600 / 48 | 630 / 50 | 5.0 / 40 | Confirm duty profile | Material Datasheet |
| Alnico 5B (Cast) | 12.2 / 1.22 | 650 / 52 | 660 / 53 | 5.5 / 44 | Confirm duty profile | Material Datasheet |
| Alnico 5DG (Cast) | 12.5 / 1.25 | 690 / 55 | 700 / 56 | 6.5 / 52 | Confirm duty profile | Material Datasheet |
| Alnico 5-7 (Cast) | 13.0 / 1.30 | 700 / 56 | 740 / 59 | 7.5 / 60 | Confirm duty profile | Material Datasheet |
| Alnico 8-HC (Cast) | 7.0 / 0.70 | 1750 / 139 | 1750 / 139 | 4.5 / 36 | Confirm duty profile | Material Datasheet |
| Alnico 8 (Cast) | 8.2 / 0.82 | 1500 / 119 | 1600 / 127 | 5.0 / 40 | Confirm duty profile | Material Datasheet |
| Alnico 8B (Cast) | 8.8 / 0.88 | 1500 / 119 | 1650 / 131 | 5.5 / 44 | Confirm duty profile | Material Datasheet |
| Alnico 8C (Cast) | 9.0 / 0.90 | 1380 / 110 | 1440 / 115 | 7.5 / 60 | Confirm duty profile | Material Datasheet |
| Alnico 9 (Cast) | 10.5 / 1.05 | 1410 / 112 | Project-specific | 9.0 / 72 | Confirm duty profile | Material Datasheet |
Reference values support initial selection; the approved drawing and agreed specification govern supply.
Grade PDF links open a dedicated grade file. Material Datasheet links open the general material reference.
Reference edition 2026.09-R1 · Magnetic quantities and conversion tools
Application & grade guidance5 reference rows
5 rows
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| Application | Typical Spec | Why this material |
|---|---|---|
| Precision instruments | Alnico 2 / 5 | Very low flux drift over temperature |
| Watt-hour meters | Alnico 5 | Long-term stable reference field |
| Reed switch actuation | Alnico 3 / 5 | Stable actuation across temperature |
| Radar / TWT / instruments | Alnico 8 / 9 | High-temperature stability |
| Educational / scientific | Alnico 2 | Classic rods / horseshoe forms |
Cast vs sintered AlNiCo2 reference rows
2 rows
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| Route | Strength | Tolerance / shape logic | Typical use |
|---|---|---|---|
| Cast | Higher energy and complex castable forms | Larger geometry; grinding on functional surfaces | Horseshoes, meters, sensors, instruments |
| Sintered | Fine grain and repeatability for small parts | Smaller precision components | Miniature sensors, magnetic circuits, instruments |
Physical properties5 reference rows
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| Property | Sintered | Cast |
|---|---|---|
| Vickers hardness | ~440 | 440–620 |
| Density | 6.8–7.0 g/cm³ | 6.9–7.3 g/cm³ |
| Curie temperature | 810–860 °C | 740–860 °C |
| Specific resistance | 50–70 μΩ·cm | 45–75 μΩ·cm |
| Thermal expansion | 11.0–12.4 ×10⁻⁶/°C | 11.0–13.0 ×10⁻⁶/°C |
Geometry & tolerances4 reference rows
4 rows
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| Route | Typical Tolerance | Notes |
|---|---|---|
| As-cast | Per agreed drawing | Economical near-net shape |
| Ground | Per agreed drawing | Pole and mounting faces |
| Sintered | Per agreed drawing | Small precision parts |
| Machining | Grinding-focused | Hard/brittle alloy; functional surfaces are normally ground |
QUALITY & RELEASE
Define the Magnetic Calibration Requirements.
Verification follows the component’s function and the agreed inspection plan.
Flux-temperature behavior
Review details
Verify the magnetic output over the agreed temperature profile rather than accepting room-temperature data alone.
Demagnetization margin
Review details
Test the worst-case opposing field or assembly condition and record the retained performance after exposure.
Geometry and surface
Review details
Inspect cast or sintered features against the drawing, including machining datum, porosity or visual limits where applicable.
Calibration and matching
Review details
For matched sets, define the measurement fixture, temperature point, sorting band and traceability record.
PRODUCT QUESTIONS
AlNiCo Circuit and Calibration.
Why use AlNiCo instead of SmCo?
AlNiCo can be attractive when very stable temperature behavior, specific cast geometries or a legacy magnetic circuit are important. SmCo may be preferred when higher coercivity or a more compact design is needed.
Can AlNiCo be used near steel?
It can, but the complete magnetic circuit must be evaluated because AlNiCo has relatively low coercivity. Nearby steel and opposing fields can change the working point.
What is the difference between cast and sintered AlNiCo?
The manufacturing route affects achievable geometry, dimensional control, surface finish and cost. The suitable route should be selected against the drawing and volume.
CONTINUE EXPLORING
Related Magnetic Solutions.
APPLICATION REVIEW
Define the AlNiCo Magnetic Circuit.
Share the working gap, steel return path and required output window.
Discuss This SpecificationSource values and conversion basis
Original source pairs retained in the source PDFs: N56 422–454 (52–57); N42SH-HRE 333–341 (42.0–43.0); N50EH 385–392 (48.5–49.2); sintered AlNiCo 8 1530 Oe / 121 kA/m.
Calculated secondary equivalents use the published primary display values: kJ/m³ for energy product, and Oe for the AlNiCo coercivity table. The ≈ symbol indicates rounded conversion, not a new measurement. Approved supply limits and source revisions are confirmed for the project.