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Steel M3-1 HT 62-64 HRC

Hardness band

UNS T11313 · AISI/SAE M3 Class 1 · GB W6Mo5Cr4V3

HT 62-64 HRC = 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.

High cost $$$$

Values for the HT 62-64 HRC condition

Other M3-1 tempers and conditions

M3-1 is listed in 4 conditions; see the grade overview at M3-1.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
AnnealedDefault
spheroidize annealed bar/blank stock
Standard as-supplied condition for bars, blanks and forging stock; soft enough to machine before hardening.55087020235 HB22 W/m·K
HT 62-64 HRCThis page
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.1,9002,200163 HRC24 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.2,1002,4000.565 HRC24 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.2,1502,4000.566 HRC2.5 % IACS

What is M3-1 HT 62-64 HRC?

M3-1 HT 62-64 HRC is M3-1 heat treated to HT 62-64 HRC — austenitize ~1190–1210 °C, oil/salt/vacuum quench, triple temper ~550–565 °C; choose when interrupted cuts or shock loading dominate. M3-1 HT 62-64 HRC has a yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of steel grades. Elongation at break is 1% and the elastic modulus is 217 GPa (31.5 Msi). M3-1 HT 62-64 HRC 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). Annealed is the default condition FabDigit quotes; HT 62-64 HRC is available on request or by drawing note.

Advantages

  • High strength — 1,900 MPa (276 ksi), better than 100% of steel grades
  • High service temperature — 540°C (1,004 °F), better than 93% of steel grades

Limitations

  • Difficult to machine — 5/100, worse than 100% of steel grades
  • Limited ductility — 1%, worse than 99% of steel grades
  • Difficult to weld — 10/100, worse than 99% 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

M3-1 HT 62-64 HRC properties

Typical room-temperature values for M3-1 HT 62-64 HRC; 18 are specific to this condition. Other listed values are M3-1 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

M3-1 HT 62-64 HRC 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).

Density8.05 g/cm³0.29 lb/in³
Melting Point (Solidus)1,250°C2,282 °F
Liquidus Temperature1,425°C2,597 °F

Mechanical15

M3-1 HT 62-64 HRC has a yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of steel grades. Elongation at break is 1% and the elastic modulus is 217 GPa (31.5 Msi).

Elastic (Young's) Modulus217 GPa31.5 Msi
Shear Modulus82 GPa11.9 Msi
Bulk Modulus165 GPa23.9 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)2,200 MPa319 ksi
Yield Strength (0.2% offset)1,900 MPa276 ksi
Elongation at Break1%
Reduction in Area30%
Compressive Strength3,300 MPa479 ksi
Shear Strength1,400 MPa203 ksi
Fatigue Strength (Endurance Limit)800 MPa116 ksi
Charpy V-Notch Impact (RT)8 J5.9 ft·lbf
Hardness, Brinell235 HB
Hardness, Rockwell B99 HRB
Hardness, Vickers790 HV

Thermal6

M3-1 HT 62-64 HRC is rated for continuous service to 540°C (1,004 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).

Thermal Conductivity24 W/m·K13.9 BTU/hr·ft·°F
Specific Heat Capacity420 J/kg·K0.1 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)10.3 µm/m·K5.7 µin/in·°F
Latent Heat of Fusion250 J/g107 BTU/lb
Max Service Temperature (continuous)540°C1,004 °F
Min Service Temperature-60°C-76 °F

Electrical3

M3-1 HT 62-64 HRC conducts electricity at 2.9 % IACS, worse than 93% of steel grades.

Electrical Conductivity2.9 % IACS
Electrical Resistivity6×10⁻⁷ Ω·m23.6 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is poor (20/100), better than 87% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.55 V
Corrosion ResistancePoor20/100
Chemical Resistance SummaryRusts readily in humid air and any aqueous/chloride exposure; requires oil, phosphate, black-oxide or PVD coating. Attacked by acids; unaffected by dry hydrocarbons and neat cutting oils.

Sustainability4

Producing a kilogram of M3-1 HT 62-64 HRC takes about 48 MJ of energy and emits 3.2 kg of CO₂ — more than 93% of steel grades. Typical recycled content is 35%.

Embodied Energy (primary production)48 MJ/kg20,636 BTU/lb
Embodied Carbon (primary production)3.2 kg CO₂/kg
Embodied Water110 L/kg13.2 gal/lb
Typical Recycled Content35%

Manufacturability8

M3-1 HT 62-64 HRC's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (10/100); formability poor (15/100).

MachinabilityNot recommended5/100
Machinability Rating (AISI 1212 = 100 %)5%
WeldabilityNot recommended10/100
Formability (cold)Poor15/100
CastabilityPoor25/100
Brazeability / SolderabilityGood55/100
PolishabilityGood55/100
Anodizing Responsen/a — ferrous alloy; use black oxide, steam-temper, nitriding or PVD (TiN/TiAlN) instead

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with M3-1 HT 62-64 HRC

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.

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.

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.

ElementSpec limit (wt %)Nominal
CASTM A600 M3 Class 11 – 1.11.05
Mn0.15 – 0.40.3
Si0.2 – 0.450.3
Cr3.75 – 4.54.1
Vhigher than M2; source of the extra wear resistance2.25 – 2.752.5
W5 – 6.756
Mo4.75 – 6.55.5
Coresidual maximum≤ 0.75—
P≤ 0.03—
S≤ 0.03—
Febalance—

M3-1 HT 62-64 HRC — frequently asked

What is M3-1 HT 62-64 HRC used for?

M3-1 HT 62-64 HRC 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 HT 62-64 HRC?

M3-1 HT 62-64 HRC has a typical yield strength of 1,900 MPa (276 ksi) and a tensile strength of 2,200 MPa (319 ksi) — stronger than 100% of steel grades. Strength varies by condition: see the 4 listed tempers.

Is M3-1 HT 62-64 HRC easy to machine?

Not especially — machinability is rated not recommended (5/100, worse than 100% 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 HT 62-64 HRC be welded?

Not readily — weldability is rated not recommended (10/100). 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 HT 62-64 HRC?

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 HT 62-64 HRC 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 HT 62-64 HRC?

M3-1 HT 62-64 HRC is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
  2. JIS G4403 — High speed tool steel (SKH52) — Japanese Standards Association (2015)
  3. GB/T 9943 — (W6Mo5Cr4V3) — SAC (2008)
  4. ASM Handbook Vol.1: Properties and Selection — Tool Steels — ASM International (1990)
  5. ASM Handbook Vol.16: Machining — ASM International (1989)
  6. 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.