Steel CPM M4 HT62-64
Hardness band
HT62-64 = hardened & tempered to 62–64 HRC
Best all-round balance of wear resistance and toughness for cutting tools and cold-work dies.
Values for the HT62-64 condition
Other CPM M4 tempers and conditions
CPM M4 is listed in 5 conditions; see the grade overview at CPM M4.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard stock condition for machining and blanking before hardening. | 550 | 850 | 12 | 23 HRC | 3.1 % IACS |
Hardened & tempered to 64–66 HRC | Use for pure abrasive wear (broaches, form tools, slitters) where impact loading is light. | 2,000 | 2,200 | 0.5 | 65 HRC | 2.5 % IACS |
Hardened, cryogenically treated and multiple tempered, 64–66 HRC | Deep-freeze cycle converts retained austenite for maximum dimensional stability and edge retention (knife/blade practice). | 2,100 | 2,300 | 0.5 | 65 HRC | 2.5 % IACS |
Hardened & tempered to 60–62 HRC | Choose when chipping/impact is the failure mode — interrupted cuts, heavy blanking punches. | — | 2,300 | — | 61 HRC | — |
HT62-64This page Hardened & tempered to 62–64 HRC | Best all-round balance of wear resistance and toughness for cutting tools and cold-work dies. | — | 2,400 | — | 63 HRC | — |
What is CPM M4 HT62-64?
CPM M4 HT62-64 is CPM M4 heat treated to HT62-64 — best all-round balance of wear resistance and toughness for cutting tools and cold-work dies. CPM M4 HT62-64 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 2,400 MPa (348 ksi) — stronger than 71% of steel grades. Elongation at break is 12% and the elastic modulus is 221 GPa (32.1 Msi). CPM M4 HT62-64 has a density of 7.97 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,250°C (2,282 °F). ANN is the default condition FabDigit quotes; HT62-64 is available on request or by drawing note.
Advantages
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Difficult to machine — 5/100, worse than 100% of steel grades
- Low fracture toughness — 22 MPa·√m (20 ksi·√in), worse than 98% of steel grades
- High embodied carbon — 5.2 kg CO₂/kg, worse than 96% of steel grades
- Poor heat conductor — 24 W/m·K (13.9 BTU/hr·ft·°F), worse than 90% of steel grades
- Limited formability — 14/100, worse than 90% of steel grades
CPM M4 HT62-64 properties
Typical room-temperature values for CPM M4 HT62-64; 11 are specific to this condition. Other listed values are CPM M4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
CPM M4 HT62-64 has a density of 7.97 g/cm³ (0.288 lb/in³), heavier than 94% of steel grades. It melts at 1,250°C (2,282 °F).
Mechanical17
CPM M4 HT62-64 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 2,400 MPa (348 ksi) — stronger than 71% of steel grades. Elongation at break is 12% and the elastic modulus is 221 GPa (32.1 Msi).
Thermal6
CPM M4 HT62-64 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 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
CPM M4 HT62-64 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 CPM M4 HT62-64 takes about 75 MJ of energy and emits 5.2 kg of CO₂ — more than 97% of steel grades. Typical recycled content is 20%.
Manufacturability6
CPM M4 HT62-64's machinability is not recommended (5/100, worse than 100% of steel grades); weldability poor (20/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CPM M4 HT62-64
Is CPM M4 easy to machine?
Machine only in the annealed condition with rigid setups, sharp carbide or cobalt HSS tooling and modest speeds; hardened parts require CBN/diamond grinding, EDM or wire EDM — PM structure grinds far better than conventional M4.
Can CPM M4 be welded?
Not a structural weld grade; repair only by preheat 480–540 °C, matched HSS/TIG filler and immediate re-temper to avoid quench cracks.
Can CPM M4 be formed, bent or molded?
Cold forming is impractical; hot work at 1040–1120 °C followed by slow cooling and full anneal, then vacuum harden at 1180–1220 °C with triple temper at 540–560 °C.
What surface finishes work on CPM M4?
No inherent corrosion resistance — finish with oil, phosphate, black oxide, or PVD (TiN/TiAlN/AlCrN) below the temper temperature; fine carbides allow good but not mirror-grade polishing.
CPM M4 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 |
|---|---|---|
| CCrucible CPM M4 HC nominal 1.42 % | 1.25 – 1.45 | 1.42 |
| Mn | 0.15 – 0.4 | 0.3 |
| Si | 0.2 – 0.6 | 0.55 |
| Cr | 3.75 – 4.75 | 4 |
| Vforms hard MC vanadium carbides | 3.75 – 4.5 | 4 |
| W | 5.25 – 6.5 | 5.5 |
| Mo | 4.25 – 5.5 | 5.25 |
| S0.06–0.15 % in sulfurized free-machining variant | ≤ 0.03 | 0.02 |
| P | ≤ 0.03 | — |
| Fe | balance | — |
CPM M4 HT62-64 — frequently asked
What is CPM M4 HT62-64 used for?
CPM M4 HT62-64 is typically used for high-performance knives, woodworking tools and cutting inserts. In short: PM high-speed wear grade; tougher than conventional M4; grinds better than wrought M4.
What is the yield strength of CPM M4 HT62-64?
CPM M4 HT62-64 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 2,400 MPa (348 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is CPM M4 HT62-64 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, sharp carbide or cobalt HSS tooling and modest speeds; hardened parts require CBN/diamond grinding, EDM or wire EDM — PM structure grinds far better than conventional M4.
Can CPM M4 HT62-64 be welded?
Not readily — weldability is rated poor (20/100). Not a structural weld grade; repair only by preheat 480–540 °C, matched HSS/TIG filler and immediate re-temper to avoid quench cracks.
What surface finishes work on CPM M4 HT62-64?
No inherent corrosion resistance — finish with oil, phosphate, black oxide, or PVD (TiN/TiAlN/AlCrN) below the temper temperature; fine carbides allow good but not mirror-grade polishing.
Can CPM M4 HT62-64 be formed, bent or molded?
Cold forming is impractical; hot work at 1040–1120 °C followed by slow cooling and full anneal, then vacuum harden at 1180–1220 °C with triple temper at 540–560 °C.
What is the maximum service temperature of CPM M4 HT62-64?
CPM M4 HT62-64 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.
What is the difference between CPM M4-ANN and CPM M4 HT-CRYO?
ANN is the default condition — standard stock condition for machining and blanking before hardening. HT-CRYO: deep-freeze cycle converts retained austenite for maximum dimensional stability and edge retention (knife/blade practice). Yield strength is 550 MPa in ANN versus 2,100 MPa in HT-CRYO.
Sources
- CPM Rex M4 / CPM M4 HC tool steel data sheet — Crucible Industries (2020)
- ASTM A600 — Tool Steel, High Speed — ASTM International (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (tool steels) — ASM International (1990)
- Tool Steels, 5th ed. — ASM International (1998)
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.