Steel M35
AISI/SAE M35
M35 is a tungsten-molybdenum high-speed tool steel — M2 (W6Mo5Cr4V2) with about 5% cobalt, EN 1.3243 / HS6-5-2-5, JIS SKH55 — where the cobalt raises the secondary-hardening temperature and red hardness to give 64-66 HRC after hardening and tempering and cutting hardness near 600 °C.
Values for the Annealed condition
M35 tempers and conditions
M35 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed bar/plate as supplied for machining | Standard mill supply condition for blanks that will be machined then hardened. | 600 | 900 | 10 | 24 HRC | 3.1 % IACS |
1190–1230 °C austenitize, triple temper 540–560 °C, 64–66 HRC | Standard cutting-tool condition: maximum red hardness and wear resistance for drills, taps, milling cutters and hobs. | 2,200 | 0.5 | 65 HRC | — |
What is M35?
M35 is a tungsten-molybdenum high-speed tool steel — M2 (W6Mo5Cr4V2) with about 5% cobalt, EN 1.3243 / HS6-5-2-5, JIS SKH55 — where the cobalt raises the secondary-hardening temperature and red hardness to give 64-66 HRC after hardening and tempering and cutting hardness near 600 °C. It is stocked as annealed bar (600 MPa yield, 900 MPa tensile, 10% elongation, 248 HB, 400 °C maximum service temperature) for drills, taps, milling cutters, broaches and tooling that cuts stainless and superalloys. Toughness and corrosion resistance are low at about 4% Cr, the heat-treatment window is narrow, and hardened parts are grind- or EDM-only; plain M2 costs less. M35 has a density of 8.1 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,260°C (2,300 °F). M35 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 10% and the elastic modulus is 217 GPa (31.5 Msi).
What is M35 used for?
- Twist drills
- Milling cutters
- Reamers
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
Limitations
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
- High embodied carbon — 4.2 kg CO₂/kg, worse than 95% of steel grades
- Poor heat conductor — 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 92% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
M35 properties
Typical room-temperature values for M35-Annealed; bars are the position among steel grades.
Physical3
M35 has a density of 8.1 g/cm³ (0.293 lb/in³), heavier than 97% of steel grades. It melts at 1,260°C (2,300 °F).
Mechanical17
M35 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 10% and the elastic modulus is 217 GPa (31.5 Msi).
Thermal5
M35 is rated for continuous service to 400°C (752 °F). It conducts heat at 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 92% of steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
M35 conducts electricity at 3.1 % IACS, worse than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of M35 takes about 60 MJ of energy and emits 4.2 kg of CO₂ — more than 96% of steel grades. Typical recycled content is 35%.
Manufacturability7
M35's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (20/100); formability poor (15/100).
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. M35 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M35
Is M35 easy to machine?
Machine only in the annealed condition with rigid setups, sharp carbide or coated HSS tooling and generous coolant; after hardening the material is essentially grind/EDM-only.
Can M35 be welded?
Not a structural weld alloy — repair only, using matching HSS filler with 500–550 °C preheat and immediate re-temper to avoid quench cracks.
Can M35 be formed, bent or molded?
Hot forge 1050–1150 °C, stop above 900 °C and cool slowly followed by a full anneal at 850–900 °C; no meaningful cold forming.
Manufacturability
The process limits FabDigit applies to M35. Every M35 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Poor30 / 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 |
M35 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 |
|---|---|---|
| CEN 1.3243 runs higher, 0.87–0.95 | 0.82 – 0.88 | 0.85 |
| Si | 0.2 – 0.45 | 0.3 |
| Mn | 0.15 – 0.4 | 0.28 |
| Cr | 3.75 – 4.5 | 4.15 |
| Mo | 4.5 – 5.5 | 5 |
| W | 5.5 – 6.75 | 6.25 |
| V | 1.75 – 2.2 | 1.95 |
| Cocobalt addition vs M2 — raises red hardness | 4.75 – 5.75 | 5 |
| P | ≤ 0.03 | |
| Smax; sulfurized free-machining versions run higher | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on M35?
Grind with soft, free-cutting wheels and ample coolant to avoid grinding burn; finish with steam oxide, black oxide, nitriding or PVD TiN/TiAlN for wear and oxidation 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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
How much does M35 cost?
M35 is a premium-cost steel ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
M35 — frequently asked
What is M35 used for?
M35 is typically used for twist drills, milling cutters and reamers. In short: high-speed cobalt tool.
What is the yield strength of M35?
M35 has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is M35 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed condition with rigid setups, sharp carbide or coated HSS tooling and generous coolant; after hardening the material is essentially grind/EDM-only.
Can M35 be welded?
Not readily — weldability is rated poor (20/100). Not a structural weld alloy — repair only, using matching HSS filler with 500–550 °C preheat and immediate re-temper to avoid quench cracks.
What surface finishes work on M35?
Grind with soft, free-cutting wheels and ample coolant to avoid grinding burn; finish with steam oxide, black oxide, nitriding or PVD TiN/TiAlN for wear and oxidation protection.
Can M35 be formed, bent or molded?
Hot forge 1050–1150 °C, stop above 900 °C and cool slowly followed by a full anneal at 850–900 °C; no meaningful cold forming.
What is the maximum service temperature of M35?
M35 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does M35 cost?
M35 is a premium-cost steel ($$$), pricier than about 57% 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 M35?
Yes — M35 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 — Tool Steel, High Speed — ASTM International (2021)
- EN ISO 4957 — Tool steels (HS6-5-2-5 / 1.3243) — CEN/ISO (2018)
- GB/T 9943 — (W6Mo5Cr4V2Co5) — SAC (2008)
- JIS G 4403 — High speed tool steels (SKH55) — JISC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (tool steels) — ASM International (1990)
- ASM Handbook Vol.16 — Machining (machinability of tool steels) — ASM International (1989)
- High speed steel HS6-5-2-5 / S705 data sheet — voestalpine Böhler Edelstahl (2022)
- Conventional HSS grades data sheet (M35 / HS6-5-2-5) — Erasteel (2021)
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.