HAP-40 is a recent reformation of ultra-hard knife blade steel. The changes are a reduction in Chromium (typically set 12-15% moved to 3.7-4.7%) which typically is used to improve corrosiveness and replacing it with increases in Cobalt, Vanadium, Tungsten and Molybdenum - the types of materials you can find in car engines :)
HAP-40 is produced by Hitachi factory in Japan.
The make up of the ingredients is as follows:
| Elements | |
| Fe | ~75% |
| C | 1.27-.1.37% |
| Cr | 3.7-4.7% |
| Mo | 4.6-5.4% |
| V | 2.8-3.3% |
| Co | 7.5-.8.5% |
| W | 5.60-6.40% |
| P | - |
| S | - |
| Quenching Hardness | ~HRC65+ |
