Lifting electromagnets

Lifting electromagnets are large, switchable magnets used to pick up and move heavy objects made of iron or steel.

• They usually contain a coil of wire wrapped around a soft iron core. When electric current flows through the coil, the core becomes strongly magnetic.
• Unlike a permanent magnet, they can be turned on and off. This lets a crane lift a pile of metal and then drop it exactly where needed.
• The magnetic force is strongest when the electromagnet is close to the metal. A flat, round lifting magnet can hold onto a steel sheet much like a powerful magnetic “hand.”
• They are useful for sorting scrap because they attract iron and steel but do not pick up materials such as wood, plastic, aluminium, or copper.
• Using an electromagnet makes work safer and faster than workers trying to attach chains or hooks to sharp, heavy pieces of metal.

Because the magnetism depends on electricity, the load must be handled carefully: if the current stops, the electromagnet releases the metal.