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Steel G20Mo5 vs WC4

Steel · grade comparison

Steel G20Mo5 and WC4 are both steel grades. WC4 is the stronger of the two: yield strength 335 MPa (48.6 ksi) against 285 MPa (41.3 ksi) for G20Mo5, about 18% more; tensile strength follows at 545 MPa (79 ksi) vs 510 MPa (74 ksi). WC4 is harder — 163 HB against 150 HB for G20Mo5 — which matters for wear surfaces and threads. WC4 runs hotter in service (540°C vs 450°C continuous). On the shop floor, G20Mo5 welds better (very good vs good).

G20Mo5Choose it when it will be welded.

WC4Choose it when strength drives the design, or when surface hardness matters.

G20Mo5 vs WC4: properties

G20Mo5WC4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
200 GPa29 Msi

Shear Modulus

81 GPa11.7 Msi
78 GPa11.3 Msi

Tensile Strength (Ultimate)

510 MPa74 ksi
545 MPa79 ksi

Yield Strength (0.2% offset)

285 MPa41.3 ksi
335 MPa48.6 ksi

Elongation at Break

25%
24%

Reduction in Area

45%
50%

Compressive Strength

285 MPa41.3 ksi
340 MPa49.3 ksi

Shear Strength

330 MPa47.9 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

215 MPa31.2 ksi
235 MPa34.1 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
48 J35.4 ft·lbf

Hardness, Brinell

150 HB
163 HB

Hardness, Rockwell B

80 HRB
85 HRB

Hardness, Vickers

158 HV
—

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

Physical

Density and transition temperatures.

Density

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

Liquidus Temperature

1,505°C2,741 °F
1,500°C2,732 °F

Same in both: Melting Point (Solidus) 1,425°C2,597 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Max Service Temperature (continuous)

450°C842 °F
540°C1,004 °F

Min Service Temperature

-30°C-22 °F
-29°C-20 °F

Same in both: 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 Resistivity

2×10⁻⁷ Ω·m7.87 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Electrical Conductivity

—
7.8 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
14 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.62 V

Manufacturability

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

Weldability

70 / 100
55 / 100

Formability (cold)

15 / 100
20 / 100

Castability

68 / 100
70 / 100

Polishability

50 / 100
45 / 100

Same in both: Machinability 58 / 100 · Machinability Rating (AISI 1212 = 100 %) 60% · Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

27 MJ/kg11,608 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
55 L/kg6.6 gal/lb

Same in both: Typical Recycled Content 75%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
70 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

193 kJ/m³
281 kJ/m³

Thermal Diffusivity

12.1 mm²/s
11.4 mm²/s

Same in both: Thermal Shock Resistance Index 9

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 scaleWC4G20Mo5

Manufacturing and finishing

CapabilityG20Mo5WC4
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.

G20Mo5 vs WC4 — frequently asked

Is WC4 stronger than G20Mo5?

Yes. WC4 has a typical yield strength of 335 MPa (48.6 ksi) against 285 MPa (41.3 ksi) for G20Mo5 — about 18% more. Tensile strength is 545 MPa (79 ksi) vs 510 MPa (74 ksi).

Which is cheaper, G20Mo5 or WC4?

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 welds better, G20Mo5 or WC4?

G20Mo5. Its weldability rates very good (70/100) against good (55/100) for WC4.

Ready to make it?

Upload a CAD file and FabDigit prices the part in G20Mo5 and WC4 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.