.020 is about 1/3 the thickness of a penny and ideal for making your own bumper magnets.
.030 is about 1/2 the thickness of a penny and provides a little more pull. Use the .030 material for heavy-duty applications or for holding papers or photos to your refrigerator.
Black on both sides.
Magnetic on one side. Will cling to smooth steel surfaces like cars, refrigerators, file cabinets, etc. Will not cling to aluminum and some other metals.
