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Steel WC4 vs ZG42CrMo

Steel · grade comparison

Steel WC4 and ZG42CrMo are both steel grades. ZG42CrMo is the stronger of the two: yield strength 680 MPa (98.6 ksi) against 335 MPa (48.6 ksi) for WC4, about 103% more; tensile strength follows at 880 MPa (128 ksi) vs 545 MPa (79 ksi). In exchange, WC4 is the more ductile: elongation 24% versus 13% for ZG42CrMo, and ZG42CrMo is harder (260 HB vs 163 HB). WC4 runs hotter in service (540°C vs 400°C continuous). On the shop floor, WC4 machines more easily (good vs fair) and WC4 welds better (good vs poor).

WC4Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

ZG42CrMoChoose it when strength drives the design.

WC4 vs ZG42CrMo: properties

WC4ZG42CrMo

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

200 GPa29 Msi
210 GPa30.5 Msi

Shear Modulus

78 GPa11.3 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

545 MPa79 ksi
880 MPa128 ksi

Yield Strength (0.2% offset)

335 MPa48.6 ksi
680 MPa98.6 ksi

Elongation at Break

24%
13%

Reduction in Area

50%
35%

Compressive Strength

340 MPa49.3 ksi
700 MPa102 ksi

Shear Strength

340 MPa49.3 ksi
530 MPa76.9 ksi

Fatigue Strength (Endurance Limit)

235 MPa34.1 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

48 J35.4 ft·lbf
35 J25.8 ft·lbf

Hardness, Brinell

163 HB
260 HB

Hardness, Rockwell B

85 HRB
—

Hardness, Rockwell C

—
26 HRC

Hardness, Vickers

—
273 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,500°C2,732 °F
1,495°C2,723 °F

Thermal

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

Max Service Temperature (continuous)

540°C1,004 °F
400°C752 °F

Min Service Temperature

-29°C-20 °F
-20°C-4 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb

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
—

Corrosion Resistance

14 / 100
12 / 100

Manufacturability

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

Machinability

58 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
50%

Weldability

55 / 100
30 / 100

Formability (cold)

20 / 100
10 / 100

Castability

70 / 100
55 / 100

Polishability

45 / 100
55 / 100

Same in both: Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

26 MJ/kg11,178 BTU/lb
24 MJ/kg10,318 BTU/lb

Embodied Water

55 L/kg6.6 gal/lb
45 L/kg5.4 gal/lb

Same in both: Embodied Carbon (primary production) 2 kg CO₂/kg · Typical Recycled Content 75%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
112 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

281 kJ/m³
1,101 kJ/m³

Thermal Shock Resistance Index

9
14

Same in both: Thermal Diffusivity 11.4 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleWC4ZG42CrMo

Manufacturing and finishing

CapabilityWC4ZG42CrMo
Default condition——
Relative cost$$ Standard$$ Standard
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.

WC4 vs ZG42CrMo — frequently asked

Is ZG42CrMo stronger than WC4?

Yes. ZG42CrMo has a typical yield strength of 680 MPa (98.6 ksi) against 335 MPa (48.6 ksi) for WC4 — about 103% more. Tensile strength is 880 MPa (128 ksi) vs 545 MPa (79 ksi).

Which is cheaper, WC4 or ZG42CrMo?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, WC4 or ZG42CrMo?

WC4. Its machinability rates good (58/100) against fair (45/100) for ZG42CrMo; for welding the order is WC4 first (good, 55/100) then ZG42CrMo (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in WC4 and ZG42CrMo 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.