H42
Data under reviewH42 is chemically a molybdenum high-speed steel (close to the M2 family) that ASTM classes with the hot work steels because of its high working hardness and hot strength. It is used for hot punches and extrusion tools needing near-HSS edge retention.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.55–0.70 |
| Si | ≤0.45 |
| Mn | ≤0.40 |
| Cr | 3.75–4.50 |
| Mo | 4.50–5.50 |
| W | 5.75–6.75 |
| V | 1.75–2.25 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Working hardness | 48–58 HRC |
| Density | 8.10 g/cm³ |
| Class note | Molybdenum high-speed composition classed as hot work |
Heat treatment
Harden 1150–1200 °C (salt/oil/air); temper 540–590 °C, triple temper.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | H42 |
Compare side by side: H42 vs M2 · H42 vs H19
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Hot punches, extrusion piercing tools, hot trimming dies, warm heading tools.
Processing: Heat treats like a high-speed steel — tight furnace control and multiple tempers are mandatory.
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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.