FabDigit

SK4 vs 1084 and 2 more: properties

SK4108410701060

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

670 MPa97.2 ksi
965 MPa140 ksi
690 MPa100 ksi
675 MPa97.9 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
585 MPa84.8 ksi
385 MPa55.8 ksi
370 MPa53.7 ksi

Elongation at Break

18%
12%
13%
17%

Reduction in Area

35%
17%
30%
34%

Compressive Strength

420 MPa60.9 ksi

Shear Strength

450 MPa65.3 ksi
580 MPa84.1 ksi
450 MPa65.3 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
420 MPa60.9 ksi
320 MPa46.4 ksi
305 MPa44.2 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
8 J5.9 ft·lbf
12 J8.9 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

190 HB
293 HB
201 HB
201 HB

Hardness, Rockwell B

92 HRB
93 HRB
93 HRB

Hardness, Vickers

200 HV
211 HV
210 HV

Hardness, Rockwell C

31 HRC

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
45 MPa·√m41 ksi·√in

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.

Density

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

Melting Point (Solidus)

1,400°C2,552 °F
1,425°C2,597 °F
1,425°C2,597 °F
1,400°C2,552 °F

Liquidus Temperature

1,465°C2,669 °F
1,470°C2,678 °F
1,480°C2,696 °F
1,470°C2,678 °F

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
11.3 µm/m·K6.3 µin/in·°F
11.5 µm/m·K6.4 µin/in·°F
11.3 µm/m·K6.3 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F
300°C572 °F
300°C572 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °F
-20°C-4 °F
-20°C-4 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
9.6 % IACS
9 % IACS
9.6 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 µΩ·in
1.8×10⁻⁷ Ω·m7.09 µΩ·in
1.9×10⁻⁷ Ω·m7.48 µΩ·in
1.8×10⁻⁷ Ω·m7.09 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
8 / 100
9 / 100
10 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V

Manufacturability

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

Machinability

45 / 100
35 / 100
45 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
45%
55%
60%

Weldability

15 / 100
20 / 100
20 / 100
25 / 100

Formability (cold)

40 / 100
30 / 100
30 / 100
30 / 100

Castability

25 / 100
45 / 100

Brazeability / Solderability

45 / 100
60 / 100
45 / 100
55 / 100

Polishability

75 / 100
75 / 100
65 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
1.9 kg CO₂/kg
2.1 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

25%
30%
25%
30%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

86 kN·m/kg
123 kN·m/kg
88 kN·m/kg
86 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

390 kJ/m³
835 kJ/m³
362 kJ/m³
334 kJ/m³

Thermal Diffusivity

13 mm²/s
13 mm²/s
13.3 mm²/s
13.3 mm²/s

Thermal Shock Resistance Index

14
20
14
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 scale108410701060SK4

Manufacturing and finishing

CapabilitySK4108410701060
CNC machiningYesYesYes
Sheet metalYesYesYes
Default conditionHRHRHR
Relative cost$ Budget$$ Standard$$ Standard$$ Standard
Min. machined wall0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µm
AlCrNYesYesYes
AlTiNYesYesYes
Black OxideYesYesYes
CVD Al2O3YesYesYes
CVD TiCNYesYesYes
CVD TiNYesYesYes
CerakoteYesYesYes
Chrome PlatingYesYesYes
CrNYesYesYes
DLCYesYesYes
E-CoatingYesYesYes
HVOF CoatingYesYesYes
Hot-Dip GalvanizingYesYesYes
MoS2YesYesYes
Multilayer CVDYesYesYes
Nickel PlatingYesYesYes
PTFE CoatingYesYesYes
PaintingYesYesYes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SK4 and 1084 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.