Magnets and electromagnets manufacturers tell you that when an iron core is inserted inside an energized solenoid, the iron core is magnetized by the magnetic field of the energized solenoid. The magnetized iron core also becomes a magnet, so that the magnetism of the solenoid is greatly enhanced due to the superposition of the two magnetic fields. In order to make the magnetism of the electromagnet stronger, the iron core is usually made into a hoof shape. However, it should be noted that the winding direction of the coil on the shoe-shaped iron core is opposite, one side must be clockwise, and the other side must be counterclockwise. Magnets and electromagnets manufacturers tell you that if the winding directions are the same, the magnetization of the two coils on the iron core will cancel each other, so that the iron core is not magnetic. In addition, the core of the electromagnet is made of soft iron, not steel. Otherwise, once the steel is magnetized, it will remain magnetic for a long time and cannot be demagnetized, and the strength of its magnetic properties cannot be controlled by the magnitude of the current, and the advantages of electromagnets will be lost.

Magnets and electromagnets manufacturers tell you that electromagnets are devices that can generate magnetic force by passing current. They are non-permanent magnets and can be easily activated or eliminated magnetically. Example: Large cranes use electromagnets to lift abandoned vehicles.
Magnets and electromagnets manufacturers tell you that when current is passed through a wire, a magnetic field is created around the wire. Using this property, when an electric current is passed through a solenoid, a uniform magnetic field is created within the solenoid. Assuming that a ferromagnetic substance is placed in the center of the solenoid, the ferromagnetic substance will be magnetized and the magnetic field will be greatly enhanced.
Generally speaking, the magnetic field produced by an electromagnet is related to the magnitude of the current, the number of turns of the coil, and the ferromagnet in the center. Magnets and electromagnets manufacturers tell you that when designing electromagnets, they will pay attention to the distribution of coils and the selection of ferromagnets, and use the magnitude of the current to control the magnetic field. The electrical resistance of the coil material limits the magnitude of the magnetic field that an electromagnet can generate, but with the discovery and application of superconductors, there will be opportunities to surpass existing limits.