Summary
P20 pre-hardened steel at 28 to 34 HRC is the default for prototype and short-run tools, while H13 at 44 to 48 HRC handles higher volume and wear. S136 stainless at 48 to 52 HRC is the choice for polished cavity surfaces, and NAK80 at 37 to 43 HRC delivers a long polish life for medical and optical parts.
Key specifications
| P20 | 28-34 HRC, general purpose, lowest cost |
|---|---|
| H13 | 44-48 HRC, high volume, good toughness |
| S136 | 48-52 HRC, stainless, high polishability |
| NAK80 | 37-43 HRC, long polish life |
| 718H | 48-52 HRC, high strength, pre-hardened |