Suspend both the magnet and the metal freely in east - west direction.
The metal will remain as it is , while the magnet will align itself in North-South direction.
The metal piece will react differently from the magnetic piece when the two are brought together.
To find out which of the otherwise identical pieces of metal is a magnet, perform the following test.
Repeat with the same end of piece
Repeat in the middle of piece
If the two pieces snap together with the same force over all three tests, you are holding the magnet piece.
If the two pieces snap together with the same force at the two ends, but not so much in the middle, you are holding the metal piece.
The force field of the magnet piece has numerous open lines of magnetic flux at each end. These lines are closed in the middle because metal is available there.
The ferrous metal piece has none of these properties and will jump at a magnet close to it from any angle.