Why is the box of a compassMade of plastic or aluminnum and not iron?

The box of a compass is typically made of plastic or aluminum rather than iron to prevent interference with the magnetic needle. Iron is magnetic, and its presence would distort the magnetic field, leading to inaccurate readings. Additionally, plastic and aluminum are lightweight, corrosion-resistant, and can be easily molded or shaped, making them practical choices for durable and portable compass designs.