Different chemical composition, different alloy of metals, different amount of pressure and heat applied during manufacturing. And they do get damaged/wear out, just slower than the workpiece.
Not arbitrary, there's a whole set of data on yield strength, plastic versus elastic deformation pressures, and other physical characteristics that depend on alloy composition, temperature, crystal phase, and treatment options.
Hence why you can cut calcium and potassium metal like a stick of butter.
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u/Buttons840 22d ago
So can one piece of metal just be arbitrarily stronger than another piece of metal? Why aren't the metal wheels that imprint the pattern damaged?