Wheel weights may have a chemical abbreviation written on them. For weights made of steel, you may see the chemical abbreviation “Fe” (for iron, the primary component of steel). The chemical abbreviation “Zn” may be visible on weights made of zinc. Both of these metals tend to be a little lighter in weight than those made of lead, so those weights should be larger than lead weights. You may want to contact the manufacturer if you have questions about the materials in your wheel weights.