Steel M3-2
UNS T11323 · AISI/SAE M3 Class 2
M3 Class 2 (M3-2, UNS T11323, SKH53) carries about 3 % vanadium, the highest of the general-purpose molybdenum high-speed steels, for top abrasion resistance in the M3 family.
Reference datasheet — M3-2 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
M3-2 tempers and conditions
M3-2 is supplied in 4 conditions, soft to hard. ANN 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 |
|---|---|---|---|---|---|---|
Hardened & triple tempered | Salt-bath/vacuum hardening near 1220 °C for maximum wear life in light, rigid cuts; toughness is minimal. | 66 HRC | — | |||
ANNDefault Annealed | Stock condition for machining tool blanks before hardening; no wear performance. | 550 | 880 | 12 | 250 HB | 24 W/m·K |
Hardened & triple tempered | Lower austenitizing (~1180 °C) for interrupted cuts, taps and larger cross-sections where chipping is the risk. | 2,200 | 0.5 | 63 HRC | 22 W/m·K | |
Hardened & triple tempered | Normal working hardness for drills, end mills, broaches and form tools needing maximum abrasion resistance. | 2,400 | 0.3 | 65 HRC | 22 W/m·K |
Supply forms, finishes and certifications
Ways M3-2 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-SO | Hardened + surface treated | Surface finish |
What is M3-2?
M3 Class 2 (M3-2, UNS T11323, SKH53) carries about 3 % vanadium, the highest of the general-purpose molybdenum high-speed steels, for top abrasion resistance in the M3 family. It is used for the most demanding wear applications and is supplied annealed as bar and tool blanks, then hardened to 62, 64 or 66 HRC with steam-oxide options. Annealed values are 880 MPa tensile, 550 MPa yield, 12 % elongation, 250 HB, 213 GPa modulus and 24 W/m·K, with service to 400 °C. Grinding is slow, weldability (18) and corrosion resistance (12) are poor; use M3-1 or M2 where toughness matters more. M3-2 has a density of 8.15 g/cm³ (0.294 lb/in³), heavier than 97% of steel grades. It melts at 1,240°C (2,264 °F). M3-2 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 71% of steel grades. Elongation at break is 12% and the elastic modulus is 213 GPa (30.9 Msi).
What is M3-2 used for?
- Cutoff tools
- Threading dies
- Heavy-duty reamers
- Broaches
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited formability — 12/100, worse than 92% of steel grades
- High embodied carbon — 3.2 kg CO₂/kg, worse than 92% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Low electrical conductivity — 3.2 % IACS, worse than 87% of steel grades
M3-2 properties
Typical room-temperature values for M3-2-ANN; bars are the position among steel grades.
Physical3
M3-2 has a density of 8.15 g/cm³ (0.294 lb/in³), heavier than 97% of steel grades. It melts at 1,240°C (2,264 °F).
Mechanical14
M3-2 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 71% of steel grades. Elongation at break is 12% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal6
M3-2 is rated for continuous service to 400°C (752 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 10.6 µm/m·K (5.89 µin/in·°F).
Electrical3
M3-2 conducts electricity at 3.2 % IACS, worse than 87% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of M3-2 takes about 42 MJ of energy and emits 3.2 kg of CO₂ — more than 92% of steel grades. Typical recycled content is 40%.
Manufacturability7
M3-2'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. M3-2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M3-2
Is M3-2 easy to machine?
Machine only in the annealed condition with rigid setups, cobalt-HSS or coated carbide and generous coolant; the ~3 % V MC carbides also make grinding slow — use SG/CBN wheels and light dressing.
Can M3-2 be welded?
Not a structural weldable steel; repair-weld only with 500–550 °C preheat, matching HSS or Co-alloy filler, immediate re-temper at 540–560 °C ×3.
Can M3-2 be formed, bent or molded?
Hot work 900–1100 °C with slow cooling and immediate anneal (860–900 °C, ≤20 °C/h to 700 °C); no meaningful cold forming.
M3-2 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 | 1.15 – 1.25 | 1.2 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.45 | 0.3 |
| Cr | 3.75 – 4.5 | 4.1 |
| W | 5 – 6.75 | 6 |
| Mo | 4.75 – 6.5 | 5.5 |
| VClass 2 = higher V than M3 Class 1 | 2.75 – 3.75 | 3.1 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on M3-2?
Harden 1190–1220 °C (vacuum/salt), quench, triple temper 540–560 °C ×1 h to 64–66 HRC; finish with steam-oxide, nitrocarburizing or TiN/TiAlN PVD (≤500 °C) plus oil film 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 M3-2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T11323
- AISI / SAE
- M3 Class 2
- Similar grades
- SKH53
How much does M3-2 cost?
M3-2 is a high-cost steel ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
M3-2 — frequently asked
What is M3-2 used for?
M3-2 is typically used for cutoff tools, threading dies, heavy-duty reamers and broaches. In short: highest-wear general-purpose HSS; about 3 % vanadium; hardest of family to grind.
What is the yield strength of M3-2?
M3-2 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 880 MPa (128 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is M3-2 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed condition with rigid setups, cobalt-HSS or coated carbide and generous coolant; the ~3 % V MC carbides also make grinding slow — use SG/CBN wheels and light dressing.
Can M3-2 be welded?
Not readily — weldability is rated poor (18/100). Not a structural weldable steel; repair-weld only with 500–550 °C preheat, matching HSS or Co-alloy filler, immediate re-temper at 540–560 °C ×3.
What surface finishes work on M3-2?
Harden 1190–1220 °C (vacuum/salt), quench, triple temper 540–560 °C ×1 h to 64–66 HRC; finish with steam-oxide, nitrocarburizing or TiN/TiAlN PVD (≤500 °C) plus oil film for rust protection.
Can M3-2 be formed, bent or molded?
Hot work 900–1100 °C with slow cooling and immediate anneal (860–900 °C, ≤20 °C/h to 700 °C); no meaningful cold forming.
What is the maximum service temperature of M3-2?
M3-2 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does M3-2 cost?
M3-2 is a high-cost steel ($$$$), 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 — Tool Steel, High Speed — ASTM International (2021)
- JIS G 4403 SKH53 — JSA (2015)
- GB/T 9943 (W6Mo5Cr4V3) — SAC (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- HS6-5-3 / 1.3344 high speed steel data sheet — Böhler / Erasteel (2020)
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.