Steel G18Mo5 vs WC4
Steel · grade comparison
Steel G18Mo5 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 G18Mo5, about 18% more; tensile strength follows at 545 MPa (79 ksi) vs 500 MPa (72.5 ksi). WC4 is harder — 163 HB against 145 HB for G18Mo5 — which matters for wear surfaces and threads. WC4 runs hotter in service (540°C vs 480°C continuous). On the shop floor, G18Mo5 welds better (very good vs good).
G18Mo5Choose it when it will be welded.
WC4Choose it when strength drives the design, or when surface hardness matters.
G18Mo5 vs WC4: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 1,425°C2,597 °F
Thermal
How each material carries heat and how hot it can run.
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Latent Heat of Fusion 270 J/g116 BTU/lb
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Weldability
Formability (cold)
Same in both: Machinability 58 / 100 · Machinability Rating (AISI 1212 = 100 %) 60% · Castability 70 / 100 · Brazeability / Solderability 45 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | G18Mo5 | WC4 |
|---|---|---|
| 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.
G18Mo5 vs WC4 — frequently asked
Is WC4 stronger than G18Mo5?
Yes. WC4 has a typical yield strength of 335 MPa (48.6 ksi) against 285 MPa (41.3 ksi) for G18Mo5 — about 18% more. Tensile strength is 545 MPa (79 ksi) vs 500 MPa (72.5 ksi).
Which is cheaper, G18Mo5 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, G18Mo5 or WC4?
G18Mo5. Its weldability rates very good (72/100) against good (55/100) for WC4.
Ready to make it?
Upload a CAD file and FabDigit prices the part in G18Mo5 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.