Steel CPM M4
CPM M4 is a Crucible Particle Metallurgy version of the M4 high-speed steel chemistry, whose fine, evenly distributed carbides give wear resistance and toughness together.
Reference datasheet — CPM M4 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
CPM M4 tempers and conditions
CPM M4 is supplied in 5 conditions, soft to hard. ANN is the default FabDigit quotes; the values on this page are for it.
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 | — | ||
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?
CPM M4 is a Crucible Particle Metallurgy version of the M4 high-speed steel chemistry, whose fine, evenly distributed carbides give wear resistance and toughness together. It is supplied annealed at 241 HB (23 HRC) with 550 MPa yield, 850 MPa tensile and 12% elongation, and heat treated to 60–62, 62–64 or 64–66 HRC with a cryogenic-treated option, in bar, plate and blank form for cutting tools and blades. Thermal conductivity is 24 W/m·K, the steel is not stainless and machinability is low (25), so hardened parts are ground or EDM'd; a PM cold-work grade such as Vanadis 4 Extra is the alternative where red hardness is not required. CPM M4 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). CPM M4 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 71% of steel grades. Elongation at break is 12% and the elastic modulus is 221 GPa (32.1 Msi).
What is CPM M4 used for?
- High-performance knives
- Woodworking tools
- Cutting inserts
Advantages
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- High embodied carbon — 5.2 kg CO₂/kg, worse than 96% of steel grades
- Difficult to machine — 25/100, worse than 93% of steel grades
- Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 90% 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 properties
Typical room-temperature values for CPM M4-ANN; bars are the position among steel grades.
Physical3
CPM M4 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 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 850 MPa (123 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 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 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 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's machinability is poor (25/100, worse than 93% of steel grades); weldability poor (20/100); formability not recommended (14/100).
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. CPM M4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CPM M4
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.
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 |
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.
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 CPM M4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- M4
How much does CPM M4 cost?
CPM M4 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.
CPM M4 — frequently asked
What is CPM M4 used for?
CPM M4 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?
CPM M4 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 71% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is CPM M4 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% 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 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?
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 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?
CPM M4 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.
How much does CPM M4 cost?
CPM M4 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
- 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; 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.