Solenoids are the largely unseen drivers of a wide range of processes in modern manufacturing, automation and industrial safety. From precise motion in medical equipment to the force required in sorting installations, these components convert electrical energy into controlled mechanical work with a level of efficiency that other actuation technologies struggle to match.
Key characteristics of industrial solenoids
Solenoids combine force, speed and controllability, which makes them well suited to demanding industrial applications:
- Precise positioning and control: ability to perform linear or rotary movements with high accuracy.
- High switching speeds: response times in the millisecond range, suitable for dynamic processes.
- Scalable force: the force generated can be adjusted through design and current control to suit each application.
- Durability and low maintenance: because they do without complex transmission mechanisms, they are particularly robust.
- Adaptability: electromagnetic devices can be designed for specific environmental conditions and performance requirements.
How an industrial solenoid works
The operating principle is based on a current-carrying coil that generates a magnetic field. This field acts on a plunger made of ferromagnetic material and moves it along a defined linear stroke. By controlling the electrical current, the force, speed and position of the plunger can be regulated precisely.
Single-acting solenoids vs bistable solenoids
Single-acting solenoids move the plunger only while current is flowing, and return to their starting position by means of a spring or an external force. They are the usual choice for simple switching, locking or tripping tasks.
By contrast, bistable or reversible solenoids can hold two stable positions and only need a short current pulse to switch from one to the other. This makes them particularly energy-efficient, as they draw no current in the holding state.
Advantages of electromagnetic systems
- High reliability and long service life, thanks to the small number of moving parts
- Fast and precise switching
- Low energy consumption, especially in bistable versions
- Direct control through simple electrical signals
- High force density in a compact space
- Virtually maintenance-free operation throughout the entire life cycle
- Can be adapted to demanding environmental conditions (temperature, humidity)
Types of industrial solenoids
Locking solenoids in access control
In industrial safety, compact locking solenoids are used to secure machine guard doors or building entrances. They provide fast, reliable, electrically controlled locking that can be integrated into higher-level access control systems. In the event of a power failure, and depending on their design, they can adopt the safe state required by the installation, either open or closed when de-energised.
Sorting solenoids in recycling
High-performance solenoids play a decisive role in automated sorting installations. They are used to separate ferromagnetic materials, such as steel, from other recyclable materials (aluminium, plastic, glass) on a conveyor belt. Fast switching of the magnetic field makes it possible to capture and divert materials accurately into the corresponding container, significantly improving the efficiency of the recycling process.
Proportional solenoids in fluid technology
In hydraulic or pneumatic systems, proportional solenoids regulate the flow of liquids or gases. Unlike simple switching solenoids, they can move the plunger to any position along its stroke, in proportion to the applied current. This enables continuous, high-precision control of pressure and flow in valves.
Why choose NAFSA for your industrial solenoids
Quality and reliability are decisive in industrial environments. Our management system, certified to ISO 9001:2015, consistently ensures high standards of product quality and process safety.
At NAFSA we design and manufacture actuating solenoids and electromagnetic devices adapted to the specific needs of each customer, from concept through to series production. We work in sectors such as automation, safety, medicine, machinery and equipment, agriculture, energy and the environment, fluid technology and automotive.
When a project requires it, we develop custom solenoids designed for specific conditions of temperature, humidity or mechanical load.
Frequently asked questions about industrial solenoids
What factors determine the force of a solenoid?
The force generated depends on several key factors: the current, the number of coil turns (ampere-turns), the size and material of the ferromagnetic core, and the air gap between the plunger and the pole core. An optimised design maximises magnetic flux density and minimises the air gap in the energised state to obtain the highest possible force.
What is the difference between a holding solenoid and a push solenoid?
The main difference lies in their primary function. A push solenoid is designed to perform a linear movement (a stroke) that does mechanical work. A holding solenoid, on the other hand, is designed to retain ferromagnetic objects through direct contact. Its force acts perpendicular to the contact surface, whereas a push solenoid exerts its force along the axis of movement.
How can the service life of a solenoid be maximised?
Service life depends largely on operating conditions. Correct sizing in terms of duty cycle (ED), ambient temperature and load profile is decisive. Avoiding overheating by respecting the specified voltage and on-time, together with protection against vibration and humidity, contributes decisively to reaching the many millions of switching cycles that a well-sized solenoid can deliver.
The guides and profiles used in each product type also play a part, ranging from the more conventional linear solenoids to high-performance solenoids.
Can solenoids be adapted to special environments?
Yes. One of the main strengths of solenoids is their adaptability. For high-temperature areas, heat-resistant insulating materials and wire can be used. For outdoor use or humid environments, coils are usually encapsulated or fitted in sealed housings with high protection ratings, protecting them against corrosion and short circuits.
From standard components to fully customised assemblies, industrial solenoids offer a combination of force, precision and reliability that is hard to match in automation, safety and sorting applications. Choosing the right type, monostable or bistable, and sizing it correctly for the process conditions is a decisive step in any engineering project.
At NAFSA we have spent years developing electromagnetic solutions for industry. If you need technical advice for your project, contact our team and we will work with you to assess the most suitable solution.