M2
1.3343 / HS6-5-2 · EN ISO 4957 · 1.3343
M2 (1.3343 / HS6-5-2) is a high-speed tool steel (Molybdenum Series family) to EN ISO 4957 (1.3343). Nominal carbon content is around 0.86 %. Supplied hardened in service; for analysis treat it as elastic (E = 210 GPa) with a hardness- or fracture-based limit. It retains hardness at the high temperatures generated in cutting (red-hardness).
Bilinear material model — nonlinear FEA
This grade is supplied hardened in service and is not represented as a bilinear material — it has a negligible uniform-plastic range. Model it as elastic (E = 210 GPa) with an appropriate fracture / hardness-based limit.
Ratings — engineering judgement
Weldabilitypoor
Higher carbon (~0.86%) raises the risk of HAZ cracking — preheat and PWHT are usually required, if welding is advisable at all.
Machinabilitypoor
Machine in the annealed condition; hard and abrasive once heat treated.
Corrosion resistancepoor
No inherent corrosion resistance — protect by paint, galvanising or plating in exposed use.
Hardenabilityexcellent
Designed to through-harden to high hardness for wear and cutting duty.
Toughnesslow
Hard and wear-resistant but low toughness — not for shock loading unless a shock-resisting grade.
Indicative ratings derived from composition and family — engineering guidance, not specification values.
Physical properties
| Density | 8000 | kg/m³ |
| Elastic modulus | 210 | GPa |
| Shear modulus | 80.8 | GPa |
| Poisson's ratio | 0.30 | |
| Thermal expansion | 11.0 | ×10⁻⁶/°C |
| Thermal conductivity | 24 | W/(m·K) |
| Specific heat | 420 | J/(kg·K) |
| Magnetic | Yes |
Typical values for molybdenum series steel — use the mill certificate for the specific product.
Chemical composition (wt %)
Nominal composition per EN ISO 4957 for M2 — confirm exact limits against the standard.
Available forms
Common applications
- Drills, taps, milling cutters and broaches
- Lathe and planer tools
- Cold-work punches for high-speed duty
History
High-speed steels are heavily alloyed (tungsten, molybdenum, chromium, vanadium, cobalt) tool steels that keep their hardness — “red hardness” — at the high temperatures generated in fast cutting, which ordinary tool steels cannot. Their invention transformed machining productivity.
- 1900Taylor & White demonstrate high-speed steel at the Paris Exposition
- 1910Tungsten (T-series) high-speed steels standardised
- 1940Molybdenum (M-series) HSS becomes dominant; cobalt grades for the hardest work
This profile is generated from the grade's core data and family. Composition is decoded from the designation where its naming system defines it; physical properties are family-typical and ratings are indicative. Confirm critical values against the governing standard or the mill certificate. Equivalents, historical designations and hand-written expert notes are added per grade over time.