Steel M2 Stress Relieved
Heat-treated state
AISI/SAE M2 · UNS T11302 · EN 1.3343, HS6-5-2 · JIS SKH51 · GB W6Mo5Cr4V2
Use between rough and finish machining of large or asymmetric tools to limit hardening distortion.
Values for the Stress Relieved condition
Other M2 tempers and conditions
M2 is listed in 5 conditions; see the grade overview at M2.
- Stress Relieved
- Annealed
- As Printed
- HIP
- Hardened & Tempered
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress RelievedThis page 600–700 °C sub-critical anneal after rough machining | Use between rough and finish machining of large or asymmetric tools to limit hardening distortion. | 560 | 880 | 13 | 20 HRC | 3.1 % IACS |
AnnealedDefault soft annealed bar/plate for machining before heat treatment | Default stocked condition: machine or grind tool blanks, then harden and temper. | 570 | 900 | 12 | 235 HB | — |
laser powder-bed fusion / DED M2 in as-built (as-quenched martensitic) state | Only for additively built tool inserts/coatings; expect residual stress, retained austenite and crack sensitivity — temper or HIP before service. | — | 1,300 | 0.4 | 61 HRC | — |
Hot isostatic pressed | Choose PM/HIP M2 for fine uniform carbides, isotropic properties and better toughness/grindability in large or intricate tools. | 1,900 | 2,200 | 1 | 65 HRC | 3 % IACS |
1190–1230 °C quench, 3× 540–560 °C temper, 64–66 HRC | Standard cutting-tool condition: maximum hardness, wear resistance and red hardness for drills, mills, taps. | — | 2,400 | 0.3 | 65 HRC | 24 W/m·K |
What is M2 Stress Relieved?
M2 Stress Relieved is M2 heat treated to Stress Relieved — use between rough and finish machining of large or asymmetric tools to limit hardening distortion. M2 Stress Relieved has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 73% of steel grades. Elongation at break is 13% and the elastic modulus is 217 GPa (31.5 Msi). M2 Stress Relieved has a density of 8.16 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; Stress Relieved is available on request or by drawing note.
Advantages
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Poor heat conductor — 21.5 W/m·K (12.4 BTU/hr·ft·°F), worse than 94% of steel grades
- High embodied carbon — 3.4 kg CO₂/kg, worse than 93% of steel grades
- Low fracture toughness — 42 MPa·√m (38.2 ksi·√in), worse than 92% of steel grades
- Limited formability — 14/100, worse than 90% of steel grades
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
M2 Stress Relieved properties
Typical room-temperature values for M2 Stress Relieved; 23 are specific to this condition. Other listed values are M2 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
M2 Stress Relieved has a density of 8.16 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
M2 Stress Relieved has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 73% of steel grades. Elongation at break is 13% and the elastic modulus is 217 GPa (31.5 Msi).
Thermal6
M2 Stress Relieved is rated for continuous service to 550°C (1,022 °F). It conducts heat at 21.5 W/m·K (12.4 BTU/hr·ft·°F), worse than 94% of steel grades. Thermal expansion is 10.1 µm/m·K (5.61 µin/in·°F).
Electrical3
M2 Stress Relieved conducts electricity at 3.1 % IACS, worse than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of M2 Stress Relieved takes about 48 MJ of energy and emits 3.4 kg of CO₂ — more than 93% of steel grades. Typical recycled content is 40%.
Manufacturability7
M2 Stress Relieved's machinability is fair (36/100, worse than 81% of steel grades); weldability poor (20/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with M2 Stress Relieved
Is M2 easy to machine?
Machine only in the annealed state with sharp cobalt-HSS or coated carbide, rigid setups and modest speeds; hardened 64–66 HRC parts require grinding, EDM or CBN.
Can M2 be welded?
Poor weldability — repair welding only, with 500–550 °C preheat, matching HSS filler, immediate post-weld temper to avoid quench cracks.
Can M2 be formed, bent or molded?
No practical cold forming; hot work at 1100–900 °C followed by slow cooling and soft annealing at 850–900 °C, then harden 1190–1230 °C and temper 2–3× at 540–580 °C.
What surface finishes work on M2?
Not anodizable; use black oxide, steam oxide, phosphate or nitriding for corrosion and lubricity, and PVD TiN/TiCN/TiAlN below the tempering temperature for wear performance.
M2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cregular-carbon M2; high-carbon variant (M2 HC) is 0.95–1.05 | 0.78 – 0.88 | 0.85 |
| W | 5.5 – 6.75 | 6.2 |
| Mo | 4.5 – 5.5 | 5 |
| Cr | 3.75 – 4.5 | 4.15 |
| V | 1.75 – 2.2 | 1.95 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.45 | 0.3 |
| Coresidual only; cobalt-bearing grade is M35/M42 | ≤ 0.5 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Febalance ≈ 80–81% | balance | — |
M2 Stress Relieved — frequently asked
What is M2 Stress Relieved used for?
M2 Stress Relieved is typically used for drill bits, milling cutters and end mills, taps and reamers, broaches, cold-work punches and blanking die inserts. In short: tough high-speed cutting.
What is the yield strength of M2 Stress Relieved?
M2 Stress Relieved has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is M2 Stress Relieved easy to machine?
Not especially — machinability is rated fair (36/100, worse than 81% of steel grades). Machine only in the annealed state with sharp cobalt-HSS or coated carbide, rigid setups and modest speeds; hardened 64–66 HRC parts require grinding, EDM or CBN.
Can M2 Stress Relieved be welded?
Not readily — weldability is rated poor (20/100). Poor weldability — repair welding only, with 500–550 °C preheat, matching HSS filler, immediate post-weld temper to avoid quench cracks.
What surface finishes work on M2 Stress Relieved?
Not anodizable; use black oxide, steam oxide, phosphate or nitriding for corrosion and lubricity, and PVD TiN/TiCN/TiAlN below the tempering temperature for wear performance.
Can M2 Stress Relieved be formed, bent or molded?
No practical cold forming; hot work at 1100–900 °C followed by slow cooling and soft annealing at 850–900 °C, then harden 1190–1230 °C and temper 2–3× at 540–580 °C.
What is the maximum service temperature of M2 Stress Relieved?
M2 Stress Relieved is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between M2 Annealed and M2-HIP?
Annealed is the default condition — default stocked condition: machine or grind tool blanks, then harden and temper. HIP: choose PM/HIP M2 for fine uniform carbides, isotropic properties and better toughness/grindability in large or intricate tools. Yield strength is 570 MPa in Annealed versus 1,900 MPa in HIP.
Can FabDigit make parts in M2 Stress Relieved?
Yes — M2 Stress Relieved is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- EN ISO 4957 — Tool steels (HS6-5-2C / 1.3343) — ISO/CEN (2018)
- JIS G 4403 — High speed tool steels (SKH51) — JSA (2015)
- GB/T 9943 — (W6Mo5Cr4V2) — SAC (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (tool steels) — ASM International (1990)
- ASM Handbook Vol.16 — Machining (machinability ratings) — ASM International (1989)
- Böhler S600 / Erasteel M2 high speed steel datasheets — voestalpine Böhler / Erasteel (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.