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Steel 6CrW2Si vs S6

Steel · grade comparison

Steel 6CrW2Si and S6 are both steel grades. 6CrW2Si is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 415 MPa (60.2 ksi) for S6, about 8% more. In exchange, S6 is the more ductile: elongation 22% versus 18% for 6CrW2Si, and 6CrW2Si is harder (240 HB vs 210 HB). 6CrW2Si runs hotter in service (400°C vs 200°C continuous) and 6CrW2Si conducts heat better (33 W/m·K vs 25 W/m·K). On the shop floor, S6 machines more easily (45 vs 35 out of 100) and 6CrW2Si sits in a lower cost tier (standard, $$) than S6 (premium, $$$).

6CrW2SiChoose it when strength drives the design, or when the part sees heat.

S6Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

6CrW2Si vs S6: properties

6CrW2SiS6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

760 MPa110 ksi
740 MPa107 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
415 MPa60.2 ksi

Elongation at Break

18%
22%

Reduction in Area

40%
45%

Compressive Strength

1,000 MPa145 ksi
430 MPa62.4 ksi

Shear Strength

500 MPa72.5 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
340 MPa49.3 ksi

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

240 HB
210 HB

Hardness, Rockwell B

99 HRB
95 HRB

Hardness, Vickers

250 HV
220 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.75 g/cm³0.28 lb/in³

Same in both: Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
25 W/m·K14.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.4 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.8×10⁻⁷ Ω·m11 µΩ·in
5.8×10⁻⁷ Ω·m22.8 µΩ·in

Electrical Conductivity

—
3 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

—
-0.6 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

35 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
50%

Formability (cold)

25 / 100
35 / 100

Castability

20 / 100
—

Brazeability / Solderability

45 / 100
30 / 100

Same in both: Weldability 20 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

35 MJ/kg15,047 BTU/lb
33 MJ/kg14,187 BTU/lb

Embodied Carbon (primary production)

2.6 kg CO₂/kg
2.4 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Typical Recycled Content

35%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
95 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.7 MN·m/kg

Modulus of Resilience

489 kJ/m³
416 kJ/m³

Thermal Diffusivity

9.1 mm²/s
7 mm²/s

Thermal Shock Resistance Index

10
7

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleS66CrW2Si

Manufacturing and finishing

Capability6CrW2SiS6
Default condition——
Relative cost$$ Standard$$$ Premium
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.

6CrW2Si vs S6 — frequently asked

Is 6CrW2Si stronger than S6?

Yes. 6CrW2Si has a typical yield strength of 450 MPa (65.3 ksi) against 415 MPa (60.2 ksi) for S6 — about 8% more. Tensile strength is 760 MPa (110 ksi) vs 740 MPa (107 ksi).

Which is cheaper, 6CrW2Si or S6?

6CrW2Si is the lower-cost material: it sits in the standard tier ($$) while S6 is premium ($$$). 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, 6CrW2Si or S6?

S6, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for 6CrW2Si.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 6CrW2Si and S6 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.