OK, this might be a stupid question, but, what happens to the metal if it is not hardened?

Say, I'm thinking of getting some 'non-hardened' metal (i.e. Carbon steel, damascus) to use on the scales, (spacer, inlay, whatever)... what would be the problem with using it as scale material?

Does it need to be hardened if you are not going to be using it as the 'buisness end'?

C utz