40CrMnNiMo8-6-4 vs M42: 33% composition overlap. Significantly different materials serving different application areas.
40CrMnNiMo8-6-4 vs M42
Side-by-side chemical composition and mechanical property comparison.
Overview
40CrMnNiMo8-6-4
1.2738
Pre-hardened mould steel with nickel addition for uniform hardness through large cross-sections. Delivered at 280-325 HB. The Ni addition (0.90-1.20%) provides better through-hardening than 1.2311/1.2312, making it suitable for large moulds with sections >400mm. Used for large injection moulds for automotive, household appliance, and furniture industry. The standard choice for large, complex mould frames. Similar to AISI P20+Ni.
M42
1.3247
Cobalt super high speed steel — 8% Co for maximum hot hardness (HRC 69 at 550°C). THE HSS for machining superalloys, titanium, and pre-hardened steels where M2 burns out. Mo-series (not W-series like T15). Reaches HRC 68-70 after hardening — among the hardest HSS grades. Also known as HS2-9-1-8 (EN) or SKH59 (JIS). Used for drills, end mills, taps, broaches, and milling cutters for difficult-to-machine materials.
| 40CrMnNiMo8-6-4 | M42 | |
|---|---|---|
| Material Number | 1.2738 | 1.3247 |
| Category | Tool Steel | Tool Steel |
| Standard | EN ISO 4957 | EN ISO 4957 |
Chemical composition (wt%)
| Element | 40CrMnNiMo8-6-4 | M42 | Overlap |
|---|---|---|---|
| C | 0.35–0.45% | 1.05–1.15% | No overlap |
| Si | 0.2–0.4% | 0–0.65% | OK |
| Mn | 1.3–1.6% | 0–0.4% | No overlap |
| P | ≤ 0.03% | 0–0.03% | OK |
Mechanical properties
| Property | 40CrMnNiMo8-6-4 | M42 | Unit |
|---|---|---|---|
| hardness_hb | 280–325 | ≤ 269 | HB |
| tensile_strength | 900–1100 | — | MPa |
| density | ≥ 7.83 | ≥ 7.98 | g/cm3 |
Compatibility Assessment
40CrMnNiMo8-6-4 and M42 have significantly different compositions (33% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is 40CrMnNiMo8-6-4 the same as M42?
40CrMnNiMo8-6-4 and M42 have a 33% composition overlap. They are generally not directly interchangeable.
Can I replace 40CrMnNiMo8-6-4 with M42?
Generally not recommended. The compositions differ significantly (33% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between 40CrMnNiMo8-6-4 and M42?
The main differences are in the following elements: C, Mn, Cr, Mo. 40CrMnNiMo8-6-4 is a Tool Steel grade, while M42 is a Tool Steel grade.
View full data for each material:
Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.