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Steel WC6 vs WC9

Steel · grade comparison

Steel WC6 and WC9 are both steel grades. Both yield at about 340 MPa — strength does not separate them. WC9 runs hotter in service (570°C vs 470°C continuous) and WC6 conducts heat better (42 W/m·K vs 37 W/m·K). On the shop floor, WC6 welds better (good vs fair) and WC6 sits in a lower cost tier (standard, $$) than WC9 (premium, $$$).

WC6Choose it when it will be welded, or when cost is the deciding factor.

WC9Choose it when the part sees heat.

WC6 vs WC9: properties

WC6WC9

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Yield Strength (0.2% offset)

340 MPa49.3 ksi
330 MPa47.9 ksi

Elongation at Break

26%
24%

Compressive Strength

345 MPa50 ksi
330 MPa47.9 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

170 HB
165 HB

Hardness, Rockwell B

87 HRB
85 HRB

Hardness, Vickers

180 HV
173 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 530 MPa76.9 ksi · Reduction in Area 50% · Shear Strength 330 MPa47.9 ksi · Fatigue Strength (Endurance Limit) 240 MPa34.8 ksi · Fracture Toughness (K_IC) 130 MPa·√m118 ksi·√in

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
37 W/m·K21.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Max Service Temperature (continuous)

470°C878 °F
570°C1,058 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -29°C-20 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

—
7.8 % IACS

Same in both: Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.6 V

Corrosion Resistance

16 / 100
20 / 100

Manufacturability

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

Machinability

55 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Weldability

65 / 100
45 / 100

Castability

75 / 100
70 / 100

Brazeability / Solderability

55 / 100
45 / 100

Polishability

50 / 100
45 / 100

Same in both: Formability (cold) 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

27 MJ/kg11,608 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

80%
75%

Common Calculations

Ratios derived from the values above.

Modulus of Resilience

279 kJ/m³
263 kJ/m³

Thermal Diffusivity

11.5 mm²/s
10.2 mm²/s

Thermal Shock Resistance Index

9
8

Same in both: Specific Strength (UTS / density) 68 kN·m/kg · Specific Stiffness (E / density) 26.4 MN·m/kg

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 scaleWC6WC9

Manufacturing and finishing

CapabilityWC6WC9
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.

WC6 vs WC9 — frequently asked

What is the difference between WC6 and WC9?

Steel WC6 and WC9 are both steel grades. Both yield at about 340 MPa — strength does not separate them. WC9 runs hotter in service (570°C vs 470°C continuous) and WC6 conducts heat better (42 W/m·K vs 37 W/m·K).

Which is cheaper, WC6 or WC9?

WC6 is the lower-cost material: it sits in the standard tier ($$) while WC9 is premium ($$$). 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, WC6 or WC9?

WC6. Its machinability rates good (55/100) against fair (50/100) for WC9; for welding the order is WC6 first (good, 65/100) then WC9 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in WC6 and WC9 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.