Steel M3-1
UNS T11313 · AISI/SAE M3 Class 1 · GB W6Mo5Cr4V3
M3 Class 1 (M3-1, UNS T11313, W6Mo5Cr4V3, SKH52) is a molybdenum high-speed steel that raises vanadium to about 2.5 % over M2 to form additional hard MC carbides.
Reference datasheet — M3-1 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 Annealed condition
M3-1 tempers and conditions
M3-1 is supplied in 4 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed bar/blank stock | Standard as-supplied condition for bars, blanks and forging stock; soft enough to machine before hardening. | 550 | 870 | 20 | 235 HB | 22 W/m·K |
Hardened & tempered to 62–64 HRC | Austenitize ~1190–1210 °C, oil/salt/vacuum quench, triple temper ~550–565 °C; choose when interrupted cuts or shock loading dominate. | 1,900 | 2,200 | 1 | 63 HRC | 24 W/m·K |
Hardened & tempered to 64–66 HRC | Full austenitizing (~1210–1230 °C) with triple temper near the secondary-hardness peak; use for drills, taps, broaches and form tools where edge life outranks toughness. | 2,100 | 2,400 | 0.5 | 65 HRC | 24 W/m·K |
Hardened, deep-cryogenic treated and tempered | Adds a −80 to −196 °C soak between quench and temper to convert retained austenite; gives ~1 HRC more and better dimensional stability for precision tools. | 2,150 | 2,400 | 0.5 | 66 HRC | 2.5 % IACS |
Supply forms, finishes and certifications
Ways M3-1 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
HT+Surface | Hardened & tempered plus surface treatment | Surface finish |
What is M3-1?
M3 Class 1 (M3-1, UNS T11313, W6Mo5Cr4V3, SKH52) is a molybdenum high-speed steel that raises vanadium to about 2.5 % over M2 to form additional hard MC carbides. Engineers specify it for longer edge life on abrasive work; it ships annealed as bar, flats and tool blanks and is heat treated to 62–64 or 64–66 HRC, with cryogenic and surface-treated options. Annealed values are 870 MPa tensile, 550 MPa yield, 20 % elongation, 235 HB, 210 GPa modulus and 22 W/m·K, with service to 400 °C. Toughness and grindability fall against M2 and corrosion resistance is minimal (score 18). M3-1 has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 96% of steel grades. It melts at 1,250°C (2,282 °F). M3-1 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 71% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
What is M3-1 used for?
- Form tools
- Broaches
- Reamers
- High-volume drills
Limitations
- Poor heat conductor — 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades
- Low electrical conductivity — 2.9 % IACS, worse than 93% of steel grades
- High embodied carbon — 3.2 kg CO₂/kg, worse than 92% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
M3-1 properties
Typical room-temperature values for M3-1-Annealed; bars are the position among steel grades.
Physical3
M3-1 has a density of 8.05 g/cm³ (0.291 lb/in³), heavier than 96% of steel grades. It melts at 1,250°C (2,282 °F).
Mechanical15
M3-1 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 71% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
M3-1 is rated for continuous service to 400°C (752 °F). It conducts heat at 22 W/m·K (12.7 BTU/hr·ft·°F), worse than 93% of steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).
Electrical3
M3-1 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 M3-1 takes about 48 MJ of energy and emits 3.2 kg of CO₂ — more than 93% of steel grades. Typical recycled content is 35%.
Manufacturability8
M3-1's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (15/100); 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. M3-1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M3-1
Is M3-1 easy to machine?
Machine only in the annealed condition with rigid setups and cobalt/carbide tooling; the 2.5 % V raises abrasive MC carbide content, so expect ~40 % of AISI 1212 and grind hardened parts with CBN or SG-alumina wheels.
Can M3-1 be welded?
Not a structural weld metal — repair only by TIG/laser with matching HSS filler at 480–540 °C preheat followed by immediate re-temper to avoid quench cracks.
Can M3-1 be formed, bent or molded?
Hot work 1050–1120 °C, stop above ~900 °C and slow-cool/anneal at 850–900 °C; no meaningful cold forming.
M3-1 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 |
|---|---|---|
| CASTM A600 M3 Class 1 | 1 – 1.1 | 1.05 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.45 | 0.3 |
| Cr | 3.75 – 4.5 | 4.1 |
| Vhigher than M2; source of the extra wear resistance | 2.25 – 2.75 | 2.5 |
| W | 5 – 6.75 | 6 |
| Mo | 4.75 – 6.5 | 5.5 |
| Coresidual maximum | ≤ 0.75 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on M3-1?
Cannot be anodized; use steam oxide, black oxide, nitriding or TiN/TiAlN PVD (below the 550 °C temper temperature) plus oiling for 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 M3-1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T11313
- AISI / SAE
- M3 Class 1
- GB (China)
- W6Mo5Cr4V3
- Similar grades
- SKH52
How much does M3-1 cost?
M3-1 is a high-cost steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
M3-1 — frequently asked
What is M3-1 used for?
M3-1 is typically used for form tools, broaches, reamers and high-volume drills. In short: higher-vanadium M2 upgrade; longer edge life; wear-biased general-purpose HSS.
What is the yield strength of M3-1?
M3-1 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is M3-1 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed condition with rigid setups and cobalt/carbide tooling; the 2.5 % V raises abrasive MC carbide content, so expect ~40 % of AISI 1212 and grind hardened parts with CBN or SG-alumina wheels.
Can M3-1 be welded?
Not readily — weldability is rated poor (15/100). Not a structural weld metal — repair only by TIG/laser with matching HSS filler at 480–540 °C preheat followed by immediate re-temper to avoid quench cracks.
What surface finishes work on M3-1?
Cannot be anodized; use steam oxide, black oxide, nitriding or TiN/TiAlN PVD (below the 550 °C temper temperature) plus oiling for rust protection.
Can M3-1 be formed, bent or molded?
Hot work 1050–1120 °C, stop above ~900 °C and slow-cool/anneal at 850–900 °C; no meaningful cold forming.
What is the maximum service temperature of M3-1?
M3-1 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does M3-1 cost?
M3-1 is a high-cost steel ($$$$), 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)
- JIS G4403 — High speed tool steel (SKH52) — Japanese Standards Association (2015)
- GB/T 9943 — (W6Mo5Cr4V3) — SAC (2008)
- ASM Handbook Vol.1: Properties and Selection — Tool Steels — ASM International (1990)
- ASM Handbook Vol.16: Machining — ASM International (1989)
- High-speed steel grade datasheets (M2/M3 class) — 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.