Plastic and fingernail, which is harder?

Question

Plastic and fingernail, which is harder?

I am trying to know if I use my fingernail to scratch a plastic material. Which will being scratched off?

Answer 1

It depends on which plastic you're talking about. Different plastics have different hardnesses, and some will be scratched by a fingernail, while others will not.

Check to see if you can find what the material is made of. Usually plastics will have an acronym printed on them that gives the chemical name - common ones are PE (polyethylene), PS (polystyrene), PVC (poly vinyl chloride), PMMA (polymethyl methacrylate), etc.

Once you know the chemical name, try checking wikipedia on that compound or typing in the name of the plastic and "Mohs hardness" or "hardness" into Google.

Oh. Also, the Mohs hardness of a fingernail is 2.5. The scale goes from 1 to 10, talc being a 1 and diamond being a 10.