Steel CPM M4 vs CPM S30V
Steel · grade comparison
Steel CPM M4 and CPM S30V are both steel grades. CPM S30V is the stronger of the two: yield strength 700 MPa (102 ksi) against 550 MPa (79.8 ksi) for CPM M4, about 27% more; tensile strength follows at 950 MPa (138 ksi) vs 850 MPa (123 ksi). In exchange, CPM M4 is the more ductile: elongation 12% versus 8% for CPM S30V. CPM S30V is lighter (7.44 g/cm³ vs 7.97 g/cm³ for CPM M4) and CPM M4 runs hotter in service (540°C vs 400°C continuous). On the shop floor, CPM M4 welds better (poor vs not recommended) and CPM S30V sits in a lower cost tier (premium, $$$) than CPM M4 (high, $$$$).
CPM M4Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
CPM S30VChoose it when strength drives the design, or when weight is the constraint.
CPM M4 vs CPM S30V: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 221 GPa32.1 Msi · Poisson's Ratio 0.28 · Hardness, Rockwell C 23 HRC
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 8
Strength versus weight
Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | CPM M4 | CPM S30V |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | Annealed |
| Relative cost | $$$$ High | $$$ Premium |
| Min. machined wall | — | 0.8 mm |
| Best machined surface | — | Ra 1.6 µm |
| AlCrN | — | Yes |
| AlTiN | — | Yes |
| Black Oxide | — | Yes |
| CVD Al2O3 | — | Yes |
| CVD TiCN | — | Yes |
| CVD TiN | — | Yes |
| Cerakote | — | Yes |
| Chrome Plating | — | Yes |
| CrN | — | Yes |
| DLC | — | Yes |
| E-Coating | — | Yes |
| HVOF Coating | — | Yes |
| Hot-Dip Galvanizing | — | Yes |
| MoS2 | — | Yes |
| Multilayer CVD | — | Yes |
| Nickel Plating | — | Yes |
| PTFE Coating | — | Yes |
| Painting | — | Yes |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
CPM M4 vs CPM S30V — frequently asked
Is CPM S30V stronger than CPM M4?
Yes. CPM S30V has a typical yield strength of 700 MPa (102 ksi) against 550 MPa (79.8 ksi) for CPM M4 — about 27% more. Tensile strength is 950 MPa (138 ksi) vs 850 MPa (123 ksi).
Which is cheaper, CPM M4 or CPM S30V?
CPM S30V is the lower-cost material: it sits in the premium tier ($$$) while CPM M4 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, CPM M4 or CPM S30V?
CPM M4, by a small margin. Both rate poor for machinability — 25/100 against 20/100 for CPM S30V; for welding the order is CPM M4 first (poor, 20/100) then CPM S30V (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in CPM M4 and CPM S30V side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.