Steel M41
AISI/SAE M41 · UNS T11341 · JIS SKH59 · GB W6Mo5Cr4V2Co5
M41 is a cobalt-alloyed molybdenum high-speed steel (T11341, W6Mo5Cr4V2Co5, SKH59) that combines high hot hardness with good toughness for cutting at extreme speeds.
Reference datasheet — M41 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the ANN condition
M41 tempers and conditions
M41 is supplied in 5 conditions, soft to hard. ANN 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 |
|---|---|---|---|---|---|---|
Stress relieved | Intermediate 600–700 °C stress relief after heavy roughing to limit distortion during subsequent hardening. | 580 | 880 | 13 | 24 HRC | 2.9 % IACS |
ANNDefault Annealed | Standard as-supplied condition for bars, blanks and forging stock; machine to shape before hardening. | 600 | 900 | 12 | 262 HB | 21 W/m·K |
Hardened & triple tempered | Peak-hardness condition for form tools and light-cut precision tooling; very low toughness, avoid interrupted cuts. | 2,000 | 2,100 | 0.5 | 69 HRC | 2.6 % IACS |
Hardened & triple tempered | Chosen for high cutting speeds and hard/abrasive workpieces where wear resistance outranks toughness. | 2,200 | 67 HRC | — | ||
Hardened & triple tempered | Balanced toughness/hardness setting for drills, taps, end mills and broaches in general steel machining. | 2,300 | 0.5 | 65 HRC | 20 W/m·K |
What is M41?
M41 is a cobalt-alloyed molybdenum high-speed steel (T11341, W6Mo5Cr4V2Co5, SKH59) that combines high hot hardness with good toughness for cutting at extreme speeds. It is stocked as annealed bar, flat stock and tool blanks at about 262 HB (900 MPa tensile, 600 MPa yield, 12 % elongation) and heat treated to 64–66, 66–68 or 68–70 HRC. Machinability is low (score 30) and corrosion resistance is poor (score 18), so hardened parts are finished only by grinding or EDM and must be oiled or coated for storage. Plain M2 is the cheaper choice when red hardness is not the limiting factor. M41 has a density of 8.16 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,250°C (2,282 °F). M41 has a yield strength of 600 MPa (87 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 77% of steel grades. Elongation at break is 12% and the elastic modulus is 220 GPa (31.9 Msi).
What is M41 used for?
- High-speed turning tools
- Drills for hard materials
- Reamers
- Aerospace tooling
Advantages
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
Limitations
- Poor heat conductor — 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades
- High embodied carbon — 3.8 kg CO₂/kg, worse than 94% of steel grades
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
- Limited formability — 12/100, worse than 92% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
M41 properties
Typical room-temperature values for M41-ANN; bars are the position among steel grades.
Physical3
M41 has a density of 8.16 g/cm³ (0.295 lb/in³), heavier than 98% of steel grades. It melts at 1,250°C (2,282 °F).
Mechanical15
M41 has a yield strength of 600 MPa (87 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 77% of steel grades. Elongation at break is 12% and the elastic modulus is 220 GPa (31.9 Msi).
Thermal6
M41 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
M41 conducts electricity at 2.9 % IACS, worse than 93% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of M41 takes about 55 MJ of energy and emits 3.8 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 40%.
Manufacturability6
M41's machinability is poor (30/100, worse than 89% 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. M41 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M41
Is M41 easy to machine?
Machine only in the annealed state with rigid setups, sharp cobalt-HSS or coated carbide and generous coolant; after hardening only grinding, EDM or superabrasive finishing is practical.
Can M41 be welded?
Not a structural weld metal — only tip/shank friction or flash welding and TIG repair with matched HSS filler, using 500–600 °C preheat and immediate re-tempering.
Can M41 be formed, bent or molded?
Hot forge 1050–1150 °C with slow furnace cooling and full spheroidize anneal at 850–900 °C; no meaningful cold formability.
M41 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 |
|---|---|---|
| C | 1.05 – 1.15 | 1.1 |
| Mn | 0.2 – 0.6 | 0.35 |
| Si | 0.15 – 0.65 | 0.35 |
| Cr | 3.75 – 4.5 | 4.1 |
| W | 6.25 – 7 | 6.6 |
| Mo | 3.25 – 4.25 | 3.75 |
| V | 1.75 – 2.25 | 2 |
| Co | 4.75 – 5.75 | 5.25 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on M41?
Austenitize ~1190–1220 °C in vacuum/salt, quench and triple temper 540–560 °C; finish with black oxide, steam-oxide or PVD TiN/TiAlN for wear and rust protection.
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).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel M41 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T11341
- GB (China)
- W6Mo5Cr4V2Co5
- JIS
- SKH59
How much does M41 cost?
M41 is a high-cost steel ($$$$), pricier than about 78% 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.
M41 — frequently asked
What is M41 used for?
M41 is typically used for high-speed turning tools, drills for hard materials, reamers and aerospace tooling. In short: cobalt HSS for hot hardness; hardens to 68–70 HRC; grind or EDM after hardening.
What is the yield strength of M41?
M41 has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is M41 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed state with rigid setups, sharp cobalt-HSS or coated carbide and generous coolant; after hardening only grinding, EDM or superabrasive finishing is practical.
Can M41 be welded?
Not readily — weldability is rated poor (18/100). Not a structural weld metal — only tip/shank friction or flash welding and TIG repair with matched HSS filler, using 500–600 °C preheat and immediate re-tempering.
What surface finishes work on M41?
Austenitize ~1190–1220 °C in vacuum/salt, quench and triple temper 540–560 °C; finish with black oxide, steam-oxide or PVD TiN/TiAlN for wear and rust protection.
Can M41 be formed, bent or molded?
Hot forge 1050–1150 °C with slow furnace cooling and full spheroidize anneal at 850–900 °C; no meaningful cold formability.
What is the maximum service temperature of M41?
M41 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 M41-ANN and M41 HT68-70?
ANN is the default condition — standard as-supplied condition for bars, blanks and forging stock; machine to shape before hardening. HT68-70: peak-hardness condition for form tools and light-cut precision tooling; very low toughness, avoid interrupted cuts. Yield strength is 600 MPa in ANN versus 2,000 MPa in HT68-70.
How much does M41 cost?
M41 is a high-cost steel ($$$$), pricier than about 78% 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.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (High-Speed Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- Cobalt high-speed steel bar datasheets (HSS M-series) — 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.