Material: Aluminum（they are not magnetic.) Size: 1.5inch*3nch thickness:0.039 inch the diameter of the hole:0.137" There are no burrs or sharp edges. But they have scratches. They are good for engraving. They can also be stamped, but not as good as engraved. You may use these to engrave your own number tag, dog tag, tree tag or other craft projects. Material: Aluminum（they are not magnetic.)