Appendix I Table of hardness values
| Metals | Vickers hardness number (HV) range from soft to hard | Ceramics | Vickers hardness number (HV) | Polymers | Vickers hardness number (HV) |
|---|---|---|---|---|---|
| Tin | 5 | Limestone | 250 | Polypropylene | 7 |
| Aluminium alloys | 25–140 | Magnesium oxide | 500 | PMMA | 20 |
| Gold | 35 | Tungsten carbide | 2500 | Polycarbonate | 14 |
| Copper | 40 | Titanium nitride | 2900 | PVC | 16 |
| Iron | 80 | Alumina | 2500 | Polyacetal | 18 |
| Mild steel | 140–280 | Zirconia | 1300 | Polystyrene | 21 |
| Ferritic stainless steel | 170–300 | Quartz | 1200 | CR39 | 40 |
| Martensitic stainless steel | 450–800 | Soda-lime silica glass | 490 | Urea Formaldehyde | 41 |
| Ausstenitic stainless steel | 180–400 | Granite | 850 | Epoxy | 45 |
| Tool steel | 700–1000 | Silicon nitride | 750 | Diamond | 10,000 |