FabDigit

SNCM439 vs 4140 and 2 more: properties

SNCM439414041504340

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
690 MPa100 ksi
860 MPa125 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
480 MPa69.6 ksi
520 MPa75.4 ksi
620 MPa89.9 ksi

Elongation at Break

15%
22%
16%
18%

Reduction in Area

40%
50%
40%
45%

Compressive Strength

640 MPa92.8 ksi
480 MPa69.6 ksi
640 MPa92.8 ksi

Shear Strength

540 MPa78.3 ksi
420 MPa60.9 ksi
560 MPa81.2 ksi
580 MPa84.1 ksi

Fatigue Strength (Endurance Limit)

430 MPa62.4 ksi
345 MPa50 ksi
390 MPa56.6 ksi
430 MPa62.4 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
110 MPa·√m100 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
40 J29.5 ft·lbf
25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

260 HB
210 HB
235 HB
285 HB

Hardness, Rockwell C

26 HRC
21 HRC
29 HRC

Hardness, Vickers

273 HV
220 HV
245 HV
300 HV

Hardness, Rockwell B

94 HRB
100 HRB

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,416°C2,581 °F
1,416°C2,581 °F
1,416°C2,581 °F

Liquidus Temperature

1,480°C2,696 °F
1,483°C2,701 °F
1,490°C2,714 °F
1,454°C2,649 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
44.5 W/m·K25.7 BTU/hr·ft·°F

Specific Heat Capacity

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

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F
400°C752 °F
400°C752 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F
-40°C-40 °F
-40°C-40 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
7.8 % IACS
7.8 % IACS
7 % IACS

Electrical Resistivity

2.48×10⁻⁷ Ω·m9.76 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.48×10⁻⁷ Ω·m9.76 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V
-0.6 V
-0.62 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

45 / 100
60 / 100
45 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
62%
50%
50%

Weldability

35 / 100
40 / 100
25 / 100
33 / 100

Formability (cold)

35 / 100
40 / 100
25 / 100
35 / 100

Brazeability / Solderability

50 / 100
55 / 100
55 / 100
55 / 100

Polishability

70 / 100
60 / 100
60 / 100
70 / 100

Castability

35 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
32 MJ/kg13,758 BTU/lb
31 MJ/kg13,328 BTU/lb
32 MJ/kg13,758 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.2 kg CO₂/kg
2.3 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb
60 L/kg7.2 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

115 kN·m/kg
88 kN·m/kg
110 kN·m/kg
121 kN·m/kg

Modulus of Resilience

938 kJ/m³
562 kJ/m³
660 kJ/m³
938 kJ/m³

Thermal Diffusivity

11.8 mm²/s
11.5 mm²/s
11.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

16
12
15
17

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg

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 scale414041504340SNCM439

Manufacturing and finishing

CapabilitySNCM439414041504340
Casting & forgingYes
Default conditionHRHRHRHR
Relative cost$$ Standard$$ Standard$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µmRa 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.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SNCM439 and 4140 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.