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Steel 6CrW2Si vs S2

Steel · grade comparison

Steel 6CrW2Si and S2 are both steel grades. Both yield at about 450 MPa — strength does not separate them. S2 is the more ductile: elongation 20% versus 18% for 6CrW2Si, and 6CrW2Si is harder (240 HB vs 200 HB). 6CrW2Si conducts heat better (33 W/m·K vs 25.5 W/m·K). On the shop floor, S2 machines more easily (45 vs 35 out of 100) and 6CrW2Si sits in a lower cost tier (standard, $$) than S2 (high, $$$$).

6CrW2SiChoose it when cost is the deciding factor.

S2Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

6CrW2Si vs S2: properties

6CrW2SiS2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
460 MPa66.7 ksi

Elongation at Break

18%
20%

Reduction in Area

40%
45%

Compressive Strength

1,000 MPa145 ksi
480 MPa69.6 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
100 J73.8 ft·lbf

Hardness, Brinell

240 HB
200 HB

Hardness, Rockwell B

99 HRB
94 HRB

Hardness, Vickers

250 HV
210 HV

Fracture Toughness (K_IC)

—
70 MPa·√m63.7 ksi·√in

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 760 MPa110 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,480°C2,696 °F
1,500°C2,732 °F

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
25.5 W/m·K14.7 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
477 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.4 µm/m·K6.9 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2.8×10⁻⁷ Ω·m11 µΩ·in
3.1×10⁻⁷ Ω·m12.2 µΩ·in

Electrical Conductivity

—
5.5 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

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%
65%

Weldability

20 / 100
15 / 100

Formability (cold)

25 / 100
35 / 100

Castability

20 / 100
25 / 100

Brazeability / Solderability

45 / 100
35 / 100

Polishability

55 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

35 MJ/kg15,047 BTU/lb
34 MJ/kg14,617 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%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
98 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.6 MN·m/kg

Modulus of Resilience

489 kJ/m³
511 kJ/m³

Thermal Diffusivity

9.1 mm²/s
6.9 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 scaleS26CrW2Si

Manufacturing and finishing

Capability6CrW2SiS2
CNC machining—Yes
Default condition—Annealed
Relative cost$$ Standard$$$$ 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.

6CrW2Si vs S2 — frequently asked

What is the difference between 6CrW2Si and S2?

Steel 6CrW2Si and S2 are both steel grades. Both yield at about 450 MPa — strength does not separate them. S2 is the more ductile: elongation 20% versus 18% for 6CrW2Si, and 6CrW2Si is harder (240 HB vs 200 HB).

Which is cheaper, 6CrW2Si or S2?

6CrW2Si is the lower-cost material: it sits in the standard tier ($$) while S2 is high ($$$$). 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, 6CrW2Si or S2?

S2, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for 6CrW2Si; for welding the order is 6CrW2Si first (poor, 20/100) then S2 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 6CrW2Si and S2 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.