Steel SKH51 vs W18Cr4V
Steel · grade comparison
Steel SKH51 and W18Cr4V are both steel grades. W18Cr4V is the stronger of the two: tensile strength 900 MPa (131 ksi) against 850 MPa (123 ksi) for SKH51, about 6% more. In exchange, SKH51 is the more ductile: elongation 20% versus 10% for W18Cr4V. SKH51 is lighter (8.16 g/cm³ vs 8.67 g/cm³ for W18Cr4V) and SKH51 runs hotter in service (400°C vs 350°C continuous). On the shop floor, SKH51 sits in a lower cost tier (premium, $$$) than W18Cr4V (high, $$$$).
SKH51Choose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
W18Cr4VChoose it when strength drives the design.
SKH51 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.
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 217 GPa31.5 Msi · Yield Strength (0.2% offset) 550 MPa79.8 ksi · Shear Strength 560 MPa81.2 ksi · Fracture Toughness (K_IC) 30 MPa·√m27.3 ksi·√in · Hardness, Brinell 240 HB · Hardness, Rockwell B 99 HRB · Hardness, Rockwell C 22 HRC
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Same in both: Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · 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 %)
Castability
Polishability
Same in both: Weldability 20 / 100 · Formability (cold) 15 / 100 · Brazeability / Solderability 55 / 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 Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Strength (UTS / density) 104 kN·m/kg · Modulus of Resilience 697 kJ/m³
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 | SKH51 | W18Cr4V |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
SKH51 vs W18Cr4V — frequently asked
Is W18Cr4V stronger than SKH51?
Yes. W18Cr4V has a typical tensile strength of 900 MPa (131 ksi) against 850 MPa (123 ksi) for SKH51 — about 6% more.
Which is cheaper, SKH51 or W18Cr4V?
SKH51 is the lower-cost material: it sits in the premium tier ($$$) while W18Cr4V 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, SKH51 or W18Cr4V?
W18Cr4V. Its machinability rates fair (35/100) against poor (30/100) for SKH51.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SKH51 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.