Eclipse Magnetics understands the needs of the product designer, machine designer, electrical engineer, safety manager and end user. Electro-holding magnets can be simple electromagnets or electropermanent magnets. Electromagnets are a wound copper coil with a central steel core within a steel housing– they only create magnetism and clamp onto mild steel when a dc electrical current is present (energise to hold).

Electropermanent magnets are electromagnets with permanent magnets inside them as well – the magnet clamps to the mild steel when no current is applied but when the dc current is applied the magnetic paths change and clamping is stopped (energise to release). The energise to release electromagnets are always "on" when no current is present.

Advantages & Disadvantages of Electromagnets


  • Extremely high clamping forces are possible
  • Over 1600N for a 65mm (2.6ins) diameter electromagnet
  • They can be connected in series or parallel (parallel is regarded as a better method) when using several
  • Electropermanent magnets stay clamped when no current is present
  • Can be operated remotely
  • 12V dc, 24V dc and 240V ac versions exist


  • Electromagnets only clamp when a current is applied
  • Electromagnets require a power supply
  • Pull force reduces as the air gap increases
  • Pull force reduces for thinner mild steel (using several smaller electromagnets is advised in such situations)

Typical Electromagnet Applications

  • Machine tools
  • Door locking / holding
  • Feeder mechanism, Short stroke / high force operation
  • Automation e.g. Textile machinery, Packaging machinery, Office machinery
  • Grill locking
  • Remote hold / releas

Example: A company required a system to clamp mild steel sections and move them around within a confined area, ideally with the ability to clamp and release on a robotic system. We supplied them with energise to release electropermanent magnets that they can control automatically at a distance to their requirements.