Bar magnets can be magnetised in two ways, either through the length or through the diameter. There are two varieties of magnetisation as they allow bar magnets to be used for a greater range of uses.
The most common bar magnet available is the variety that has been magnetised through the diameter.
On some bar magnets, the north pole is indicated by a notch.
Bar magnet keeper
Some types of bar magnets have two steel keepers that need removing before use, to allow the magnets to work to their full potential.
Bar magnet adhesive
Some types of bar magnet are supplied with a high tack adhesives on one side. Used as re-closable closure for folders.