How Flexible Magnets Are Magnetized: Pole Pitch and Multipole Magnetization

Flexible magnetic sheeting may look uniform, but its magnetic surface is not necessarily one continuous north or south pole.

Many flexible magnetic materials are magnetized using a repeating pattern of alternating north and south magnetic poles. This is known as multipole magnetization.

The spacing and arrangement of these poles influence how the magnetic field behaves near the surface — and can significantly affect how the material performs when attached to steel or used as part of a magnetic system.

Table of Contents

• 1. What Is Multipole Magnetization?
• 2. Why Are Flexible Magnets Commonly Multipole Magnetized?
• 3. What Is Pole Pitch?
• 4. How Does Pole Pitch Affect the Magnetic Field?
• 5. Pole Pitch and Working Distance
• 6. Does a Smaller Pole Pitch Mean More Holding Force?
• 7. Why Does the Steel Target Matter?
• 8. How Does an Air Gap Affect Multipole Flexible Magnets?
• 9. How Does Material Thickness Fit Into the Equation?
• 10. Magnet-to-Steel vs Magnet-to-Magnet Applications
• 11. Can You See the Magnetic Pole Pattern?
• 12. Why Pole Pitch Matters When Selecting Flexible Magnetic Material
• 13. Frequently Asked Questions

---

1. What Is Multipole Magnetization?

A permanent magnet requires a defined magnetization pattern.

With some rigid magnets, the pattern can be relatively simple. For example, a disc magnet may be magnetized through its thickness, with one broad pole region associated with each flat face.

Flexible magnetic sheeting is often different.

Instead of relying on one large pole region, many flexible magnetic materials use multiple alternating north and south pole regions arranged across the magnetized surface.

A simplified representation might look like this:

The actual magnetic pattern is not normally visible to the eye, and the number, spacing and geometry of the pole regions depend on the product.

2. Why Are Flexible Magnets Commonly Multipole Magnetized?

Flexible magnetic materials are frequently used against steel at very short working distances.

Examples include:

• removable magnetic signs;
• vehicle graphics;
• warehouse labels;
• retail displays;
• magnetic strips;
• printed magnetic graphics;
• industrial identification;
• removable panels and components.

For these applications, the objective is generally not to project a magnetic field over a large distance. Instead, the material needs useful attraction when it is placed directly against — or very close to — a suitable ferromagnetic surface.

A multipole pattern can create short magnetic flux paths between neighbouring pole regions and the steel target.

3. What Is Pole Pitch?

Pole pitch describes the spacing associated with a repeating magnetic pole pattern.

In practice, it is important to understand exactly how a manufacturer defines and measures pole pitch, because terminology and measurement conventions may vary.

Conceptually, however, pole pitch tells us how closely the repeating magnetic pole regions are positioned across the magnetized surface.

A flexible magnetic material may therefore have:

• relatively closely spaced pole regions;
• more widely spaced pole regions;
• or a specialized magnetization pattern designed for a particular application.

4. How Does Pole Pitch Affect the Magnetic Field?

The spacing of alternating poles affects the shape and distribution of the magnetic field above the surface of the flexible magnet.

With relatively close pole spacing, neighbouring north and south regions are close together. Much of the useful magnetic interaction is therefore concentrated near the surface.

With wider pole spacing, the field can extend differently into the space above the magnet.

This creates an important engineering trade-off:

Pole Pattern	General Field Behaviour	Application Consideration
Closer pole spacing	Magnetic interaction tends to be concentrated closer to the surface	Can be useful for close-contact applications
Wider pole spacing	Field distribution can extend differently from the surface	May be advantageous in some applications with greater separation

These are general trends rather than universal performance rules. The final result also depends on material formulation, thickness, magnetization level, target steel and system geometry.

5. Pole Pitch and Working Distance

Working distance is the separation between the magnetic material and the surface or object with which it must interact.

For many flexible magnetic applications, this distance is extremely small because the magnetic sheet is placed directly against steel.

This is where a multipole surface pattern can be particularly effective.

As separation increases, however, the magnetic field available to interact with the target changes. A pole configuration optimized for close contact should not automatically be assumed to be optimal at a larger working distance.

There is no universal equation stating that a particular pole pitch will produce a particular holding force at a particular distance for every flexible magnetic product.

For more information about working distance in magnetic systems, see SSKC-023 — Magnet Working Distance Explained.

6. Does a Smaller Pole Pitch Mean More Holding Force?

Not necessarily.

It is tempting to assume that more poles or closer pole spacing automatically means a stronger flexible magnet. That conclusion is too simple.

Holding performance depends on the complete system, including:

• magnetic material formulation;
• magnetic particle loading;
• material thickness;
• magnetization level;
• pole geometry;
• pole pitch;
• target steel;
• surface contact;
• air gap;
• load direction;
• test method.

A smaller pole pitch may change the near-surface field in a useful way, but it does not guarantee that one material will have greater holding force than another.

7. Why Does the Steel Target Matter?

The target steel is part of the magnetic circuit.

When flexible magnetic sheeting is placed against steel, magnetic flux travels through the target material and helps complete the magnetic path between pole regions.

The resulting attraction can therefore be influenced by:

• steel thickness;
• steel grade and magnetic properties;
• surface flatness;
• coatings;
• paint;
• corrosion;
• contamination;
• available contact area.

Changing the steel can change the performance even when the flexible magnetic material remains exactly the same.

This is why magnetic performance should be evaluated as a magnet-to-target system, rather than as a property of the magnetic sheet alone.

For a deeper explanation of the role of steel, see SSKC-011 — How Steel Thickness Affects Magnet Holding Force.

8. How Does an Air Gap Affect Multipole Flexible Magnets?

An air gap is any non-magnetic separation between the magnetic material and its ferromagnetic target.

It does not have to be literal air.

An effective air gap can be created by:

• paint;
• vinyl;
• protective films;
• laminates;
• adhesive layers;
• surface texture;
• dirt;
• uneven contact;
• another non-magnetic material.

Because multipole flexible magnets are often designed to work at very short distances, separation between the magnet and steel can be especially important to application performance.

However, there is no universal percentage that can be used to predict the loss caused by a particular gap. The result depends on pole spacing, material construction, magnetization, target steel and geometry.

For more information, see SSKC-012 — The Air Gap Effect.

9. How Does Material Thickness Fit Into the Equation?

Pole pitch is only one part of the flexible magnet design.

Material thickness can influence how much magnetic material is present, the stiffness of the sheet and its magnetic performance. But thickness and pole pitch should not be treated as independent indicators of quality.

Two flexible magnetic products of the same thickness can perform differently if they use different:

• material formulations;
• magnetic particle concentrations;
• magnetization levels;
• pole patterns;
• manufacturing processes.

Likewise, a thicker product is not automatically the correct choice for every application.

The objective is to match the complete magnetic construction to the required performance and working conditions.

10. Magnet-to-Steel vs Magnet-to-Magnet Applications

Most discussions of flexible magnetic sheeting involve attaching the magnet to steel. Magnet-to-magnet applications require additional consideration.

Two multipole flexible magnets will not necessarily align attractively in every position.

The pole patterns must interact correctly.

If corresponding pole regions oppose one another, the materials may repel locally. If the patterns are offset, attraction can vary as one sheet moves relative to the other.

For applications where two flexible magnetic materials must mate together, compatible pole orientation, pole spacing and registration may therefore be important.

11. Can You See the Magnetic Pole Pattern?

The magnetic pole pattern is generally invisible to the naked eye.

However, magnetic viewing film can make the pattern visible by responding to variations in the magnetic field near the surface.

On a multipole flexible magnet, the film can reveal a repeating pattern corresponding to the magnetized regions.

This can be useful for:

• confirming that a surface is magnetized;
• visualizing pole spacing;
• comparing magnetization patterns;
• checking orientation;
• investigating magnet-to-magnet alignment.

Magnetic viewing film shows the field pattern, but it does not by itself identify which visible region is north and which is south.

Determining magnetic polarity requires an appropriate polarity indicator, Hall-effect instrument or another suitable measurement method.

12. Why Pole Pitch Matters When Selecting Flexible Magnetic Material

For many everyday applications, the customer may never need to specify pole pitch directly.

Instead, the material can be selected based on the required application performance.

However, understanding pole pitch becomes increasingly useful when:

• comparing flexible magnetic constructions;
• designing around an air gap;
• working at a defined distance;
• developing magnet-to-magnet systems;
• trying to understand unexpected holding performance;
• specifying a custom magnetic construction;
• evaluating why two apparently similar materials behave differently.

Pole pitch is therefore an important engineering variable — but it is one component of the complete magnetic system, not a standalone measure of magnet quality or strength.

13. Frequently Asked Questions

What does multipole magnetization mean?

Multipole magnetization means that multiple magnetic pole regions are arranged across the magnetic surface, typically in an alternating north-south pattern. This is common in flexible magnetic sheeting intended for close contact with steel.

What is pole pitch?

Pole pitch describes the spacing associated with a repeating magnetic pole pattern. The exact measurement convention can vary, so specifications should be interpreted according to the manufacturer’s definition.

Does more poles mean a stronger magnet?

Not automatically. Pole count and spacing affect field distribution, but holding performance also depends on material formulation, thickness, magnetization level, target steel, air gap, contact area and test conditions.

Is a smaller pole pitch always better?

No. Closer pole spacing can be advantageous for some short-distance applications, but the appropriate pattern depends on the required working distance and complete magnetic system.

Why are flexible magnets usually designed for close contact?

Many flexible magnetic products use multipole surface magnetization that concentrates useful magnetic interaction near the surface. This makes them particularly suitable for applications where the magnetic material contacts or nearly contacts steel.

Can two flexible magnetic sheets attract each other?

They can, but their pole patterns and orientation must be compatible. Two multipole sheets should not automatically be assumed to form a reliable matched pair.

Can I see the poles on flexible magnetic sheeting?

Not normally with the naked eye. Magnetic viewing film can reveal the field pattern, although it does not by itself identify north versus south polarity.

Does pole pitch affect performance through paint or vinyl?

It can. Paint, vinyl and other non-magnetic layers increase the effective separation between the magnet and target. How strongly this affects performance depends on the pole pattern and the rest of the magnetic system.

---

Safety & Application Reminder

Magnetic specifications measured under controlled conditions do not automatically predict the performance of a finished application.

Where holding performance is important, evaluate the complete system using the actual flexible magnetic material, target steel, coatings, air gap, load direction and environmental conditions.

---

Start With the Flexible Magnetic Fundamentals

If you are new to flexible magnetic materials, begin with SSKC-026 — Flexible Magnetic Sheeting Explained: How Does It Work?.

It explains the basic construction of flexible magnets, how they interact with steel and the factors that influence real-world holding performance.

---

Need Help With a Flexible Magnetic Application?

Tell us what you are trying to attach, the target surface, required dimensions, working distance, printing or adhesive requirements and operating environment.

Simple Signman — a leading Canadian source for flexible magnetic materials and neodymium magnets.

Sharing our magnetic expertise since 1969.