Steel M2
AISI/SAE M2 · UNS T11302 · EN 1.3343, HS6-5-2 · JIS SKH51 · GB W6Mo5Cr4V2
M2 is the general-purpose tungsten–molybdenum high-speed steel (W6Mo5Cr4V2 / HS6-5-2 / SKH51), hardened and tempered to 63–66 HRC with red hardness to about 550–600 °C.
Values for the Annealed condition
M2 tempers and conditions
M2 is supplied in 5 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
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?
M2 is the general-purpose tungsten–molybdenum high-speed steel (W6Mo5Cr4V2 / HS6-5-2 / SKH51), hardened and tempered to 63–66 HRC with red hardness to about 550–600 °C. It offers the best balance of cutting performance and cost for drills, milling cutters, taps, broaches and cold-work punches, and it machines readily in the annealed condition (235 HB) before heat treatment. Toughness is limited and edges are notch sensitive, the ~4% Cr gives poor corrosion resistance, weldability and cold formability are poor, and heat treatment needs a narrow window with vacuum or salt-bath austenitizing and multiple tempers to control retained austenite. M2 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). M2 has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 74% of steel grades. Elongation at break is 12% and the elastic modulus is 217 GPa (31.5 Msi).
What is M2 used for?
- Drill bits
- Milling cutters and end mills
- Taps and reamers
- Broaches
- Cold-work punches
- Blanking die inserts
- Saw blades and form tools
Advantages
- 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 — 40 MPa·√m (36.4 ksi·√in), worse than 92% of steel grades
- Limited formability — 12/100, worse than 92% of steel grades
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
M2 properties
Typical room-temperature values for M2-Annealed; bars are the position among steel grades.
Physical3
M2 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 has a yield strength of 570 MPa (82.7 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 74% of steel grades. Elongation at break is 12% and the elastic modulus is 217 GPa (31.5 Msi).
Thermal6
M2 is rated for continuous service to 400°C (752 °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 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 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's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (18/100); formability not recommended (12/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. M2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M2
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.
Manufacturability
The process limits FabDigit applies to M2. Every M2 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair35 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
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 |
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.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel M2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T11302
- EN / DIN / Werkstoff-Nr.
- 1.3343HS6-5-2
- GB (China)
- W6Mo5Cr4V2
- JIS
- SKH51
- Also called
- 6541
How much does M2 cost?
M2 is a specialty-cost steel ($$$$$), pricier than about 98% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
M2 — frequently asked
What is M2 used for?
M2 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?
M2 has a typical yield strength of 570 MPa (82.7 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 74% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is M2 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% 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 be welded?
Not readily — weldability is rated poor (18/100). 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?
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 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?
M2 is rated for continuous use to about 400°C (752 °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.
How much does M2 cost?
M2 is a specialty-cost steel ($$$$$), pricier than about 98% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in M2?
Yes — M2 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.