What are the parts of a horseshoe magnet?

Magnetic poles

The north and south poles of a horseshoe magnet are placed side by side to create a short magnetic circuit, which makes the magnet stronger. This is because the magnetic field lines do not have a very long distances to travel between the two magnetic poles.

Horseshoe magnets do not have an indicator, such as a notch, to show which is the north or south pole. However to tell which is which there are a variety of different techniques, for example, using a compass.

For more information see page How to determine the polarity of an unmarked magnet.

Air gap

The air gap separates the two magnetic poles, and is created when the metal is bent into shape. The two magnetic poles need to be separated by an air gap in order to create an open circuit for the flux lines (magnetic field lines) to move and attract ferromagnetic materials between the two magnetic poles.

Clearance hole

There can either be one or two clearance holes on a horseshoe magnet which can be used to attach the horseshoe magnet to different devices e.g. an inspection mirror. The mounting screws for a horseshoe magnet must be non-magnetic to make sure the magnet does not become demagnetised.

Keeper

The steel keeper on a horseshoe magnet must be removed before use to allow the magnet to work to its full potential.