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Steel SCr445 vs SNC631

Steel · grade comparison

Steel SCr445 and SNC631 are both steel grades. SCr445 is the stronger of the two: yield strength 860 MPa (125 ksi) against 750 MPa (109 ksi) for SNC631, about 15% more; tensile strength follows at 1,030 MPa (149 ksi) vs 900 MPa (131 ksi). In exchange, SNC631 is the more ductile: elongation 20% versus 14% for SCr445, and SCr445 is harder (302 HB vs 269 HB). SNC631 runs hotter in service (400°C vs 350°C continuous). On the shop floor, SNC631 machines more easily (good vs fair) and SNC631 welds better (fair vs poor).

SCr445Choose it when strength drives the design.

SNC631Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SCr445 vs SNC631: properties

SCr445SNC631

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

1,030 MPa149 ksi
900 MPa131 ksi

Yield Strength (0.2% offset)

860 MPa125 ksi
750 MPa109 ksi

Elongation at Break

14%
20%

Reduction in Area

45%
58%

Compressive Strength

880 MPa128 ksi
760 MPa110 ksi

Shear Strength

620 MPa89.9 ksi
560 MPa81.2 ksi

Fatigue Strength (Endurance Limit)

480 MPa69.6 ksi
430 MPa62.4 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
95 J70.1 ft·lbf

Hardness, Brinell

302 HB
269 HB

Hardness, Rockwell C

32 HRC
27 HRC

Hardness, Vickers

318 HV
283 HV

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.

Density

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

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °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

42 W/m·K24.3 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-25°C-13 °F
-60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Corrosion Resistance

12 / 100
13 / 100

Manufacturability

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

Machinability

42 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

25 / 100
35 / 100

Formability (cold)

20 / 100
30 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

60 / 100
65 / 100

Castability

—
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
32 MJ/kg13,758 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2.4 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

132 kN·m/kg
115 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

1,786 kJ/m³
1,372 kJ/m³

Thermal Diffusivity

11.3 mm²/s
10.3 mm²/s

Thermal Shock Resistance Index

17
14

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 scaleSCr445SNC631

Manufacturing and finishing

CapabilitySCr445SNC631
Default condition——
Relative cost$ Budget$ Budget
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.

SCr445 vs SNC631 — frequently asked

Is SCr445 stronger than SNC631?

Yes. SCr445 has a typical yield strength of 860 MPa (125 ksi) against 750 MPa (109 ksi) for SNC631 — about 15% more. Tensile strength is 1,030 MPa (149 ksi) vs 900 MPa (131 ksi).

Which is cheaper, SCr445 or SNC631?

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

Which is easier to machine, SCr445 or SNC631?

SNC631. Its machinability rates good (55/100) against fair (42/100) for SCr445; for welding the order is SNC631 first (fair, 35/100) then SCr445 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SCr445 and SNC631 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.