M42 vs X155CrVMo12-1: 40% composition overlap. Significantly different materials serving different application areas.
M42 vs X155CrVMo12-1
Side-by-side chemical composition and mechanical property comparison.
Overview
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.
X155CrVMo12-1
1.2379
High-performance cold work tool steel with 12% Cr for exceptional wear resistance and good toughness. Air or oil hardening. The most widely used high-alloy cold work steel for demanding stamping and forming applications. Achieves 58-62 HRC. Used for blanking dies, punching tools, cold-forming dies, thread rolling dies, deep drawing tools, and industrial knives for heavy-gauge sheet. Similar to AISI D2 but with optimized V content.
| M42 | X155CrVMo12-1 | |
|---|---|---|
| Material Number | 1.3247 | 1.2379 |
| Category | Tool Steel | Tool Steel |
| Standard | EN ISO 4957 | EN ISO 4957 |
Chemical composition (wt%)
| Element | M42 | X155CrVMo12-1 | Overlap |
|---|---|---|---|
| C | 1.05–1.15% | 1.5–1.6% | No overlap |
| Si | 0–0.65% | 0.1–0.6% | OK |
| Mn | 0–0.4% | 0.2–0.6% | Partial |
| P | 0–0.03% | ≤ 0.03% | OK |
Mechanical properties
| Property | M42 | X155CrVMo12-1 | Unit |
|---|---|---|---|
| hardness_hrc | 68–70 | 58–62 | HRC |
| e_modulus | ≥ 210 | — | GPa |
| density | ≥ 7.98 | ≥ 7.7 | g/cm3 |
Compatibility Assessment
M42 and X155CrVMo12-1 have significantly different compositions (40% overlap). These materials are not interchangeable and serve different application areas.
Automated assessment based on composition analysis
Frequently Asked Questions
Is M42 the same as X155CrVMo12-1?
M42 and X155CrVMo12-1 have a 40% composition overlap. They are generally not directly interchangeable.
Can I replace M42 with X155CrVMo12-1?
Generally not recommended. The compositions differ significantly (40% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between M42 and X155CrVMo12-1?
The main differences are in the following elements: C, Mn, Cr, Mo. M42 is a Tool Steel grade, while X155CrVMo12-1 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.