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MAGNETIC MATERIALS

AlNiCo MagnetsStable flux.
Purposeful alloy design.

Cast and sintered magnets for stable flux and elevated-temperature applications.

Review My AlNiCo Application Compare Cast and Sintered Grades

Application overview

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.

AlNiCo Magnets

FORMS & CONFIGURATIONS

Made for Your Design.

Representative product forms. Final geometry, dimensions and material are confirmed against your drawing.

Cast shapes — Cast shapes
Complex geometry produced by the cast route
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Sintered parts — Sintered parts
Small parts with tighter dimensional control
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Rings — Rings
Ring geometry for instrumentation
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Segments — Segments
Segment geometry for legacy magnetic circuits
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DESIGN & SELECTION

Review the Complete Magnetic Circuit.

Illustration · Working magnetic circuit · Not to scale

01
Pole faces
Define orientation and functional surfaces
02
Magnetic circuit
Review working gap and reverse fields
03
Assembly sequence
Confirm magnetization and handling plan

Choose a review categoryCast AlNiCoSintered AlNiCo

Select a category to see the inputs to confirm.

Review This Configuration

Selection 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

Start with the Right Inputs.

A clear specification connects magnetic performance with a practical manufacturing route.

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

Grade / Route	Br	Hc	Hci	(BH)max	Max Operating Temp*	PDF
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	450°C	Material Datasheet
Alnico 5 (Sintered)	11.0 / 1.10	600 / 48	≥600 / 48	4.25 / 34	450°C	Material Datasheet
Alnico 8 (Sintered)	8.8 / 0.88	1530 / 121	≥1600 / 127	5.25 / 42	450°C	Material Datasheet
Alnico 5 (Cast)	12.2 / 1.22	600 / 48	630 / 50	5.0 / 40	500°C	Material Datasheet
Alnico 5B (Cast)	12.2 / 1.22	650 / 52	660 / 53	5.5 / 44	500°C	Material Datasheet
Alnico 5DG (Cast)	12.5 / 1.25	690 / 55	700 / 56	6.5 / 52	500°C	Material Datasheet
Alnico 5-7 (Cast)	13.0 / 1.30	700 / 56	740 / 59	7.5 / 60	525°C	Material Datasheet
Alnico 8-HC (Cast)	7.0 / 0.70	1750 / 139	1750 / 139	4.5 / 36	525°C	Material Datasheet
Alnico 8 (Cast)	8.2 / 0.82	1500 / 119	1600 / 127	5.0 / 40	525°C	Material Datasheet
Alnico 8B (Cast)	8.8 / 0.88	1500 / 119	1650 / 131	5.5 / 44	525°C	Material Datasheet
Alnico 8C (Cast)	9.0 / 0.90	1380 / 110	1440 / 115	7.5 / 60	525°C	Material Datasheet
Alnico 9 (Cast)	10.5 / 1.05	1410 / 112	1440 / 139	9.0 / 72	525°C	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.

Application & grade guidance5 reference rows

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

Reference values support initial selection; the approved drawing and agreed specification govern supply.

Cast vs sintered AlNiCo2 reference rows

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

Reference values support initial selection; the approved drawing and agreed specification govern supply.

Physical properties6 reference rows

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
Reversible temperature coefficient Br	≈ −0.02 to −0.03%/°C	≈ −0.02 to −0.03%/°C

Reference values support initial selection; the approved drawing and agreed specification govern supply.

Geometry & tolerances4 reference rows

Route	Typical Tolerance	Notes
As-cast	±0.3–0.5 mm	Economical near-net shape
Ground	±0.05 mm	Pole and mounting faces
Sintered	±0.05 mm	Small precision parts
Machining	Grinding-focused	Hard/brittle alloy; functional surfaces are normally ground

Reference values support initial selection; the approved drawing and agreed specification govern supply.

QUALITY & RELEASE

Agree the Evidence.

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.

Our Quality Approach

PRODUCT QUESTIONS

Before You Send a Drawing.

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.

FROM YOUR DRAWING TO PRODUCTION

Bring Your Design to Production.

Share your drawing. Define the next step.

Start a Technical Review