• Sep 09, 2026

SSKC-018 - Magnetization Direction Explained: Axial, Diametrical and Multipole Magnets

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Magnetization Direction Explained: Axial, Diametrical and Multipole Magnets

Document ID: SSKC-018
Series: Engineering Series
Difficulty: Intermediate
Reading Time: 10–12 minutes
Last Updated: September 2026

Why Trust Simple Signman?

Since 1969, Simple Signman has supplied magnetic materials to Canadian manufacturers, printers, sign professionals, distributors, and industrial businesses.

When selecting a permanent magnet, customers often focus on dimensions, shape, and grade. But another specification can be just as important: the direction in which the magnet is magnetized.

Two magnets can have identical dimensions, the same grade, and the same coating yet produce completely different external magnetic fields if their magnetization directions are different.

This guide explains axial, diametrical, through-thickness, through-length, multipole, and radial magnetization—and why pole orientation matters in real-world applications.

Introduction

A magnet's shape tells you what the magnet looks like.

Its magnetization direction tells you where its magnetic poles are located.

That distinction can completely change how the magnet behaves.

Magnet shape tells you what the magnet looks like. Magnetization direction tells you where the poles are.

For example, two identical disc magnets can both be made from N42 neodymium and have the same diameter and thickness.

One may be axially magnetized, with north and south poles on the two flat faces.

The other may be diametrically magnetized, with north and south poles on opposite sides of the curved circumference.

They are physically identical—but functionally very different.

Contents

What Is Magnetization Direction?

Magnetization direction describes the direction through the magnet in which the magnetic poles are established.

In simple terms, it tells you where the north pole and south pole are located on the magnet.

For a simple permanent magnet, the magnetic field travels externally from the north pole toward the south pole and returns through the magnet internally.

The same physical shape can often be magnetized in more than one direction.

Engineering Insight

Two magnets with identical dimensions and grade can produce completely different external magnetic fields if they are magnetized in different directions.

Why Magnetization Direction Matters

Magnetization direction affects:

  • where the working pole faces are located;
  • the shape of the external magnetic field;
  • how the magnet interacts with steel;
  • sensor activation;
  • attraction and repulsion between magnets;
  • pull-force direction;
  • working distance;
  • assembly design.

This means magnetization direction should never be treated as a minor drawing note.

In many applications, it is a functional specification.

Axial Magnetization Explained

Axial magnetization is common in disc, cylinder, and ring magnets.

The magnet is magnetized along its central axis.

For an axially magnetized disc:

TOP FACE
   N
─────────
  MAGNET
─────────
   S
BOTTOM FACE

One flat face is predominantly north and the opposite flat face is predominantly south.

This configuration is widely used for:

  • direct holding against steel;
  • stacking magnets face-to-face;
  • mounting applications;
  • pot magnets;
  • magnetic closures.

Diametrical Magnetization Explained

Diametrical magnetization is different.

The magnet is magnetized across its diameter rather than through its thickness.

For a diametrically magnetized disc or cylinder:

        N
   ┌─────────┐
   │ MAGNET  │
   └─────────┘
        S
Across the diameter

In practical terms, one side of the curved surface is predominantly north and the opposite side is predominantly south.

This configuration is often useful for:

  • rotational sensors;
  • position detection;
  • magnetic encoders;
  • specialized couplings;
  • applications where the field must vary as the magnet rotates.

Engineering Insight

An axially magnetized disc and a diametrically magnetized disc may look identical, but they are not interchangeable.

Through-Thickness Magnetization

Through-thickness magnetization is common for flat block magnets, plates, and sheets.

The poles are located on the two large opposing faces.

TOP FACE
N N N N N
──────────
  MAGNET
──────────
S S S S S
BOTTOM FACE

This configuration is often selected when the largest faces are intended to interact with steel or another magnet.

Typical applications include:

  • mounting;
  • clamping;
  • closures;
  • flat assemblies;
  • magnetic fixtures.

Through-Length and Through-Width Magnetization

Block magnets can also be magnetized through their length or width.

For example:

THROUGH LENGTH

N |──────────── MAGNET ────────────| S

or:

THROUGH WIDTH

      N
┌────────────┐
│   MAGNET   │
└────────────┘
      S

The correct choice depends on which faces must become the working poles.

This is why a block magnet drawing should clearly define both:

  • dimensions;
  • magnetization direction.

Multipole Magnetization Explained

Multipole magnetization places several alternating north and south poles on the same working surface or around a circumference.

A simple multipole surface pattern may look like this:

WORKING FACE

N | S | N | S | N | S | N | S

Multipole patterns are common in:

  • flexible magnetic sheeting;
  • magnetic strips;
  • rotary encoders;
  • magnetic couplings;
  • motors;
  • specialized sensor systems.

The number of poles, pole pitch, and pattern geometry can significantly affect the usable magnetic field.

Single-Pole vs Multipole: An Important Distinction

The phrase “single-pole magnet” is often used informally, but it can be misleading.

Every conventional permanent magnet has both a north pole and a south pole.

In many industrial conversations, “single pole” actually means that one broad face presents predominantly one polarity while the opposite face presents the opposite polarity.

Through-Thickness Magnetization

TOP FACE
N N N N N N
────────────
   MAGNET
────────────
S S S S S S
BOTTOM FACE

Multipole Magnetization

TOP FACE
N S N S N S N S
────────────────
   MAGNET
────────────────
S N S N S N S N
BOTTOM FACE

These two products can behave very differently even if their thickness and material are similar.

Best Practice

When requesting a “single-pole” flexible magnet from a supplier, define the desired pole arrangement explicitly—for example, “one face predominantly north, opposite face predominantly south, magnetized through thickness.”

Disc Magnets: Axial vs Diametrical

Feature Axial Diametrical
Pole location Flat faces Opposite sides of diameter
Typical holding use Very common Less common
Rotational sensing Possible in some systems Often useful
Field changes with rotation Depends on setup Strongly useful in many encoder designs

Block Magnets and Magnetization Direction

Block magnets require especially careful specification because several magnetization directions may be possible.

A block measuring:

40 × 20 × 5 mm

could potentially be magnetized through:

  • the 5 mm thickness;
  • the 20 mm width;
  • the 40 mm length.

Those three versions would create different working pole faces and different external fields.

For procurement, the dimensions alone are therefore incomplete.

Ring Magnets and Radial Magnetization

Ring magnets are commonly axially magnetized, with poles on the two flat annular faces.

However, specialized ring magnets can also be radially magnetized.

In a simplified radial configuration, the inner and outer cylindrical surfaces carry opposite polarities.

OUTER SURFACE = N
   ╔═══════════╗
   ║   RING    ║
   ╚═══════════╝
INNER SURFACE = S

Radially magnetized rings can be useful in:

  • motors;
  • specialized couplings;
  • rotating assemblies;
  • sensor systems.

They are specialized products and should not be confused with ordinary axially magnetized ring magnets.

Flexible Magnets and Multipole Patterns

Flexible magnetic materials are commonly magnetized using multiple alternating poles.

This helps create useful attraction at short working distances against steel.

Common variables include:

  • pole pitch;
  • number of poles;
  • pole orientation;
  • sheet thickness;
  • magnetization pattern.

A standard flexible magnetic sheet may use a striped multipole pattern rather than a simple through-thickness north/south arrangement.

This distinction is important when a customer requires a specific field geometry for sensing, coupling, or specialized industrial use.

How Magnetization Direction Changes the Magnetic Field

Magnetization direction determines where the poles are located, which in turn controls the external field pattern.

This affects:

  • field concentration;
  • field symmetry;
  • working distance;
  • sensor response;
  • interaction with neighboring magnets;
  • interaction with steel.

The same magnet geometry can therefore behave differently simply by changing the direction of magnetization.

Magnetization Direction vs Surface Gauss

Surface gauss depends strongly on where the measurement is taken relative to the magnet's poles.

If two physically identical magnets are magnetized differently, a gaussmeter placed at the same physical point may produce very different readings.

This does not necessarily indicate a quality problem.

It may simply mean that the magnetic pole is located elsewhere.

Engineering Insight

Gauss readings should always be interpreted together with magnetization direction and probe location.

See SSKC-015 — Magnetic Flux Density Explained: What Gauss and Tesla Really Mean.

Magnetization Direction vs Pull Force

Pull force depends heavily on which pole face is presented to the target steel.

An axially magnetized disc is naturally suited to direct pull testing on one flat face.

A diametrically magnetized disc has a very different field orientation and may not provide the same direct holding performance when placed flat against steel.

This is why published pull-force values should always correspond to the intended magnetization direction and mounting orientation.

See SSKC-001 — How Strong Are Neodymium Magnets? Pull Force Explained.

Magnetization Direction vs Working Distance

The external magnetic field decays with distance, but the shape of that field depends on pole orientation.

This matters in applications involving:

  • Hall sensors;
  • reed switches;
  • encoders;
  • magnetic couplings;
  • position sensing;
  • plastic housings;
  • air gaps.

The best magnetization direction may therefore depend on where the field is needed, not simply where the magnet fits mechanically.

Sensors, Encoders and Position Detection

Sensor applications are among the clearest examples of why magnetization direction matters.

A Hall-effect sensor may require a specific field polarity and orientation at the sensor location.

A rotating diametrically magnetized disc can create a changing field direction as it rotates.

A multipole ring can generate repeated north-south transitions for encoder feedback.

Typical applications include:

  • rotation detection;
  • speed sensing;
  • position sensing;
  • door and lid detection;
  • motor feedback;
  • industrial automation.

Magnetic Assemblies and Pole Orientation

In assemblies containing multiple magnets, pole orientation must be controlled carefully.

Possible arrangements include:

  • north facing north;
  • north facing south;
  • alternating poles;
  • Halbach-style arrangements;
  • multipole arrays.

Changing the orientation of one magnet can alter:

  • attraction;
  • repulsion;
  • field concentration;
  • assembly force;
  • sensor response.

Assembly drawings should therefore identify polarity and orientation clearly.

How to Specify Magnetization Direction to a Supplier

When sourcing custom magnets, avoid vague descriptions such as:

“Magnetized normally.”

Instead, specify exactly what is required.

For a Disc Magnet

Example: Axially magnetized through thickness, one flat face north and opposite flat face south.

For a Block Magnet

Example: Magnetized through the 5 mm thickness.

For a Rod Magnet

Example: Magnetized through the 30 mm length, poles on the two end faces.

For Flexible Magnetic Sheet

Example: Single broad pole per face, magnetized through thickness; one face predominantly north, opposite face predominantly south; no striped multipole pattern.

For Multipole Material

Specify:

  • number of poles;
  • pole pitch;
  • pattern direction;
  • working surface;
  • required polarity sequence.

Best Practice

Include a simple pole diagram on the drawing whenever magnetization direction is critical. A drawing is often clearer than terminology alone.

Engineering Recommendations

Best Practice

  • Specify magnetization direction on every custom magnet drawing.
  • Identify the working pole faces.
  • Define north/south orientation where polarity matters.
  • Do not assume a disc magnet is always axially magnetized.
  • Do not assume a ring magnet is always axially magnetized.
  • Define multipole count and pole pitch when relevant.
  • Verify magnetization direction before approving production samples.
  • Measure gauss at a defined location and orientation.
  • Test the magnet in the actual application geometry.
  • Use a pole-indicator film or gaussmeter when verification is required.

Expert Tip

If a magnet sample appears “weak” or behaves unexpectedly, confirm the magnetization direction before assuming the material grade is incorrect.

Common Mistakes

Common Mistake Why It Matters
Specifying dimensions only Pole location may remain ambiguous
Assuming all discs are axial Diametrical versions exist and behave differently
Using “single pole” without a diagram Supplier interpretation may differ
Ignoring multipole pitch Pole spacing changes field behaviour
Comparing gauss at the wrong location The pole may not be under the probe
Reversing polarity in assembly Attraction can become repulsion
Approving samples without polarity verification Production may match dimensions but fail functionally

Frequently Asked Questions

What does magnetization direction mean?

Magnetization direction describes the direction through the magnet in which the north and south poles are established.

What is axial magnetization?

Axial magnetization places the poles on opposite ends of the magnet's axis. For a disc, this usually means one flat face is north and the opposite flat face is south.

What is diametrical magnetization?

Diametrical magnetization places the poles on opposite sides across the diameter of a disc or cylinder.

Can two identical magnets have different pole directions?

Yes. Magnets with identical dimensions, grade, and coating can be magnetized in different directions and therefore behave differently.

What is multipole magnetization?

Multipole magnetization creates several alternating north and south poles on a working surface or around a circumference.

What does “single pole” mean?

In industrial usage, “single pole” often means one broad face presents predominantly one polarity and the opposite face presents the other. It does not mean a permanent magnet has only one magnetic pole.

Are flexible magnets usually multipole?

Yes. Many flexible magnetic sheets and strips use alternating multipole patterns because they provide useful attraction at short working distances.

Can a flexible magnet be magnetized through thickness?

Yes, depending on material and manufacturing capability. A through-thickness configuration can present predominantly one polarity on one face and the opposite polarity on the other.

What is radial magnetization?

Radial magnetization is used in specialized ring or cylindrical magnets where the inner and outer cylindrical surfaces carry opposite polarities.

How do I verify magnetization direction?

Common methods include magnetic viewing film, a pole indicator, a compass, or a gaussmeter used with a defined measurement procedure.

Does magnetization direction affect pull force?

Yes. Pull force depends on how the working pole faces interact with the target steel. A magnet oriented with the wrong pole geometry may provide significantly different holding performance.

Canadian Perspective

Canadian manufacturers frequently source custom magnets and magnetic assemblies from suppliers in Canada, the United States, Europe, and Asia.

Terminology for magnetization direction is not always used consistently between suppliers.

For custom production, drawings should clearly show:

  • magnet dimensions;
  • magnetization direction;
  • north and south pole locations;
  • working face;
  • multipole pitch when applicable;
  • critical tolerances.

This is especially important when qualifying alternate suppliers, because a replacement magnet can match the size and grade perfectly yet fail in the application if the pole orientation is different.

Safety Reminder

Magnetization direction affects where strong attractive and repulsive forces occur.

Unexpected pole orientation can cause magnets to snap together, repel suddenly, rotate in an assembly, or move unexpectedly during installation.

Powerful neodymium magnets can cause pinch injuries, chip or fracture on impact, and damage sensitive equipment.

For critical assemblies, verify pole orientation before installation and use appropriate engineering safety factors and secondary retention where required.

Conclusion

Magnetization direction is one of the most important—and most frequently overlooked—magnet specifications.

It determines where the magnetic poles are located and therefore influences:

  • field direction;
  • working pole faces;
  • pull force;
  • working distance;
  • sensor response;
  • attraction and repulsion;
  • assembly behaviour.

Common magnetization configurations include:

  • axial;
  • diametrical;
  • through thickness;
  • through length;
  • through width;
  • multipole;
  • radial.

Magnet shape tells you what the magnet looks like. Magnetization direction tells you where the poles are—and that can completely change how the magnet works.

When specifying a custom magnet, always define dimensions, grade, and magnetization direction together.

Need Help Specifying Magnetization Direction?

The Simple Signman team helps Canadian manufacturers, designers, distributors, sign professionals, and industrial businesses evaluate permanent magnets and custom magnetic assemblies.

When requesting assistance, provide:

  • magnet shape;
  • dimensions;
  • grade;
  • desired pole locations;
  • magnetization direction;
  • working distance;
  • required holding force or sensor response;
  • assembly drawing, if available;
  • required quantities.

We can help translate your application requirement into a clear magnetization specification for sourcing and production.

Contact Simple Signman →

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Next: SSKC-019 — Magnet Polarity Explained: North, South, Attraction and Repulsion

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