D5
Data under reviewD5 is the cobalt-bearing member of the D-family: essentially D2 chemistry plus about 3% cobalt. The cobalt lifts hot hardness and tempering resistance, suiting dies that run warm.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 1.40–1.60 |
| Si | 0.10–0.60 |
| Mn | 0.20–0.60 |
| Cr | 11.00–13.00 |
| Mo | 0.70–1.20 |
| V | 0.80–1.20 |
| Co | 2.50–3.50 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness (hardened) | 58–62 HRC |
| Density | 7.80 g/cm³ |
| Hot hardness | Better than D2 |
Heat treatment
Harden 1020–1050 °C air/oil; temper 500–540 °C for secondary hardness and dimensional stability.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | D5 |
Compare side by side: D5 vs D2 · D5 vs D4
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Hot blanking and trimming dies, warm forming tools, dies for heated stock, extrusion backers.
Processing: Similar to D2 but more costly; high-temperature tempering is preferred to exploit the cobalt effect.
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Ask for a quotationVisit NasteelSource: ASTM A681 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.