Steel M42 vs W18Cr4V
Steel · grade comparison
Steel M42 and W18Cr4V are both steel grades. M42 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for W18Cr4V, about 13% more. M42 is the more ductile: elongation 12% versus 10% for W18Cr4V, and M42 is harder (255 HB vs 240 HB). M42 is lighter (7.98 g/cm³ vs 8.67 g/cm³ for W18Cr4V) and M42 runs hotter in service (400°C vs 350°C continuous). On the shop floor, W18Cr4V sits in a lower cost tier (high, $$$$) than M42 (specialty, $$$$$).
M42Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
W18Cr4VChoose it when cost is the deciding factor.
M42 vs W18Cr4V: 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Tensile Strength (Ultimate) 900 MPa131 ksi · Reduction in Area 20% · Fatigue Strength (Endurance Limit) 400 MPa58 ksi
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)
Max Service Temperature (continuous)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Galvanic Potential (seawater, vs SCE)
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 20 / 100 · Castability 20 / 100 · Brazeability / Solderability 55 / 100 · Polishability 80 / 100
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 Shock Resistance Index
Same in both: Thermal Diffusivity 6.6 mm²/s
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 | M42 | W18Cr4V |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$$$$ Specialty | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
M42 vs W18Cr4V — frequently asked
Is M42 stronger than W18Cr4V?
Yes. M42 has a typical yield strength of 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for W18Cr4V — about 13% more. Tensile strength is 900 MPa (131 ksi) vs 900 MPa (131 ksi).
Which is cheaper, M42 or W18Cr4V?
W18Cr4V is the lower-cost material: it sits in the high tier ($$$$) while M42 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose M42 over W18Cr4V?
Pick M42 when strength drives the design, or when the part is bent, formed or impact-loaded. Pick W18Cr4V when cost is the deciding factor.
Ready to make it?
Upload a CAD file and FabDigit prices the part in M42 and W18Cr4V 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.