Steel 4150 vs SCM440
Steel · grade comparison
Steel 4150 and SCM440 are both steel grades, both high strength steel. SCM440 is the stronger of the two: yield strength 590 MPa (85.6 ksi) against 520 MPa (75.4 ksi) for 4150, about 13% more. SCM440 is harder — 255 HB against 235 HB for 4150 — which matters for wear surfaces and threads. On the shop floor, SCM440 machines more easily (good vs fair), SCM440 welds better (fair vs poor), and SCM440 forms better (fair vs poor).
SCM440Choose it when strength drives the design, or when surface hardness matters.
4150 vs SCM440: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Compressive Strength
Fracture Toughness (K_IC)
Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,416°C2,581 °F
Thermal
How each material carries heat and how hot it can run.
Latent Heat of Fusion
Same in both: Thermal Conductivity 42.6 W/m·K24.6 BTU/hr·ft·°F · Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Polishability
Same in both: Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 11.5 mm²/s · Thermal Shock Resistance Index 15
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 | 4150 | SCM440 |
|---|---|---|
| Default condition | HR | HR |
| Relative cost | $$$ Premium | $$ Standard |
| Min. machined wall | 0.8 mm | 0.8 mm |
| Best machined surface | Ra 1.6 µm | Ra 1.6 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.
4150 vs SCM440 — frequently asked
Is SCM440 stronger than 4150?
Yes. SCM440 has a typical yield strength of 590 MPa (85.6 ksi) against 520 MPa (75.4 ksi) for 4150 — about 13% more. Tensile strength is 880 MPa (128 ksi) vs 860 MPa (125 ksi).
Which is cheaper, 4150 or SCM440?
SCM440 is the lower-cost material: it sits in the standard tier ($$) while 4150 is premium ($$$). 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, 4150 or SCM440?
SCM440. Its machinability rates good (55/100) against fair (45/100) for 4150; for welding the order is SCM440 first (fair, 40/100) then 4150 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4150 and SCM440 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.