While you need sophisticated equipment to make strong permanent magnets, you can easily make a weak bar magnet. An unmagnetized piece of steel or iron, stroked in a particular way by a strong magnet, will pick up magnetism from the magnet. Unmagnetized metal has tiny magnetic parts that are disorganized. The stroking causes some of them to point in one direction. Their small magnetic fields add up to a larger one.
Hold the steel bar flat on a table so one end is pointing toward you.
Touch one end (north or south) of the bar magnet to end of the steel bar closest to you.
Move the magnet along the steel bar’s length until you reach the end away from you. The steel bar should remain still. You’re moving the magnet, not the steel bar.
Pull the magnet away a few inches, keeping the same end pointing toward the bar.
Bring that end of the magnet to the end of the steel bar nearest to you again.
Repeat this stroking motion at least 20 times. Each time, when you reach the end of the steel bar, pull the magnet away slightly, then bring it back to the end of the steel bar closest to you.
Set the magnet down and see if you can pick up loose staples with the steel bar. When it does, it is magnetized.
Permanent magnets will gradually lose their magnetism. Encounters with other magnets, drops to the floor, and heat will decrease a magnet’s strength.