Magnetism is a technical reality that many companies deal with every day, often without delving into how it actually works. Yet, it underpins lifting systems, material separation, industrial automation, sensors, precision equipment and much more.

Understanding what magnetism is means better understanding how to choose the right technologies, how to improve their efficiency, and how to apply them strategically in production processes.

This article is intended for those working in the industrial sector who want a clear, practical and up-to-date overview of:

• what is meant by magnetism;
• what a magnetic field and a magnetic flux are;
• which materials respond best to magnetism;
• how these concepts translate into real operational solutions.

A technical yet accessible guide, useful for anyone who has to make decisions, invest in machinery or choose technological partners, such as Zanetti Magneti, specialists in the sector.

Magnetism is a measurable physical phenomenon and fundamental to the operation of many industrial technologies. It is not just a theory: it is what makes possible actions such as lifting scrap metal, moving steel sheets, clamping components on machine tools, activating sensors with extreme precision, powering trains, and confining and stabilising plasma in nuclear fusion plants.

On a scientific level, magnetism arises from the movement of electric charges, in particular electrons within atoms. When this movement is disordered, nothing significant happens. But when it is organised – for example in an electric circuit or in certain ferromagnetic materials – a magnetic field is created: an area in which a force can be exerted on other materials.

In other words, magnetism manifests itself whenever electrical energy and matter interact according to precise rules. It is one of the four fundamental forces of nature, but unlike the others (such as gravitational force), it can be controlled, directed and exploited in production processes.

Devices based on these principles include:

• Industrial electromagnets, used for lifting, separation, clamping or gripping ferrous materials
• Electric motors and transformers, present in every automated system
• Magnetic separation systems, essential in the recycling, construction and steel industries

For companies, therefore, understanding what magnetism consists of means having the tools to assess higher-performance technologies, reduce waste and improve operational efficiency.

The most magnetic materials are ferromagnetic ones. This means that, when exposed to a magnetic field, they are easily magnetised and can also retain (part of) their magnetism once the field is removed.

Among the main ones:

• Iron

Without doubt the most widespread and widely used material in the field of magnetism. It responds excellently to magnetic fields, is inexpensive, easy to work with and available in large quantities. It is the basis of many magnetic cores used in industry.

• Cobalt

It has strong magnetic properties, superior to iron under certain conditions. It is mainly used in special alloys where very high performance is required, including in environments with extreme temperatures.

• Nickel

It responds well to magnetic fields and is often used in combination with other metals. Its anti-corrosive properties make it ideal in environments where durability, as well as magnetic strength, is essential.

Pure iron: the best in terms of magnetisation

Among all ferromagnetic materials, pure iron achieves the highest levels of magnetisation. This is why it is chosen as the core of many industrial electromagnets, where concentrating and amplifying the field generated by the coil is essential.

In systems developed by Zanetti Magneti, material selection is never left to chance: every electromagnet is designed with the most suitable iron for the specific application, taking into account factors such as:

• Type of load to be lifted or held
• Frequency of use
• Environmental conditions (dust, temperature, vibrations, etc.)
• Need for rapid response or continuous force

The magnetic field is a key concept in electrotechnics and industry. In simple terms, it is the area of influence around a magnetic object (or an electric current), in which a force capable of attracting or repelling other materials, especially ferromagnetic ones, is exerted.

But it is not just theory: it is precisely this invisible field that allows, for example, an electromagnet to lift a steel sheet, a sensor to detect the presence of a metal, or an electric motor to generate movement.

There are two main ways of creating a magnetic field:

• With permanent magnets

These are materials that maintain constant magnetisation over time. They generate a stable but non-adjustable field.

• With electromagnets

These are devices in which a conducting coil crossed by electric current generates a temporary magnetic field. This type of field can be switched on and off, and adjusted, making it extremely useful in industry.

In the case of industrial electromagnets, such as those designed by Zanetti Magneti, the field is further intensified by inserting a ferromagnetic core (typically soft iron) inside the coil. This allows the field to be concentrated and multiplied, greatly improving operational performance.

The magnetic field is the heart of every active magnetic device. Understanding how it works means being able to:

• Optimise plant performance
• Predict and control the effectiveness of electromagnets and sensors
• Design more efficient layouts in line with operational needs
• Reduce energy consumption while maintaining high magnetic performance

Magnetic field intensity is the measure indicating how strong the magnetic force generated at a point is, and is expressed in Ampere per metre (A/m). In practice, it determines whether an electromagnet will be able to hold a metal part firmly, lift heavy scrap, or accurately lock a component during machining.

In industry, knowing and controlling field intensity is fundamental, because it:

• Determines the attraction capacity of the electromagnet
• Influences magnetic penetration depth
• Conditions the response of the material to be attracted or held

Magnetic flux indicates the amount of magnetic field passing through a surface. In physics it is represented by the Greek letter Φ (phi) and measured in Weber (Wb).

To make it more intuitive, we can imagine it as the “flow of magnetism” passing through an area: the greater the flux, the stronger and more effective the interaction with ferrous materials.

What does magnetic flux depend on?

Three main factors determine the value of magnetic flux:

• The intensity of the magnetic field: the stronger the field, the greater the flux.
• The area crossed: a larger surface allows a greater amount of field to pass.
• The orientation of the surface: if perpendicular to the lines of force, the flux is maximum; if tilted, it decreases.

For companies and technicians, knowing magnetic flux means being able to optimise the efficiency of electromagnets and ensuring that the generated force is suitable for the application, whether lifting, separating or clamping.

A fundamental parameter for measuring the effectiveness of a magnetic system is magnetic flux density, also known as magnetic induction. It is expressed in Tesla (T) and indicates how concentrated the magnetic field is at a precise point.

The higher the density, the more effective and high-performing the magnetic field is, with concrete benefits such as:

• Greater ability to attract ferrous materials, even heavy or bulky ones, as in scrap handling

• Deeper penetration into metals, useful in complex applications such as iron recovery from demolitions
• Reliable and consistent holding even in dynamic or demanding conditions

Anyone designing plants or using electromagnets knows well that controlling magnetic flux density is not a technical detail, but an essential condition to:

• avoid energy losses,
• maintain high and constant performance,
• optimise consumption by reducing waste,
• ensure operational safety at every stage of work.

Understanding and managing concepts such as field intensity, flux and magnetic density is not just theory: it means translating physics into tangible benefits for your company. Greater efficiency in processes, greater precision in machining, greater reliability in daily operations.

This is precisely the approach at Zanetti Magneti, where for years we have been designing and producing tailor-made magnetic solutions, developed for different sectors and specific requirements.

If you want to find out how magnetism can improve the productivity of your plant or business, contact us with no obligation: our team will guide you in choosing the solution best suited to your needs.

Is magnetism always present in ferrous materials?

No. Only ferromagnetic materials can be strongly magnetised. However, even these require the presence of an external magnetic field to activate their response.

Are iron and steel both magnetic?

Iron is, but steel depends on its composition. Some types of steel (especially stainless steel) have a very weak or no magnetic response.

Can a magnetic field be dangerous?

It depends on its intensity. In industrial contexts, systems are designed to operate safely. However, it is important to comply with regulations and protect sensitive devices.

Can electromagnets be adjusted?

Yes. Unlike permanent magnets, an electromagnet is fully controllable: you can adjust its strength by changing the current or the number of turns in the coil.

Does magnetism affect electronics?

Yes. Strong magnetic fields can interfere with electronic devices. This is why correct design is essential, especially in automated systems.

What is the difference between magnetic field and magnetic flux?

The magnetic field is the force at a point, while flux is the total amount of force passing through a surface. They are two different but closely related quantities.