FabDigitFabDigit

Steel 4140 vs HC380LA

Steel · grade comparison

Steel 4140 and HC380LA are both steel grades, both high strength steel. 4140 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 420 MPa (60.9 ksi) for HC380LA, about 14% more; tensile strength follows at 690 MPa (100 ksi) vs 490 MPa (71.1 ksi). 4140 is harder — 210 HB against 150 HB for HC380LA — which matters for wear surfaces and threads. 4140 runs hotter in service (425°C vs 300°C continuous). On the shop floor, HC380LA welds better (excellent vs fair) and HC380LA forms better (good vs fair).

4140Choose it when strength drives the design, or when surface hardness matters.

HC380LAChoose it when it will be welded.

4140 vs HC380LA: properties

4140HC380LA

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

690 MPa100 ksi
490 MPa71.1 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
420 MPa60.9 ksi

Elongation at Break

22%
23%

Reduction in Area

50%
—

Compressive Strength

480 MPa69.6 ksi
—

Shear Strength

420 MPa60.9 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

345 MPa50 ksi
225 MPa32.6 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
—

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

210 HB
150 HB

Hardness, Rockwell B

94 HRB
80 HRB

Hardness, Vickers

220 HV
158 HV

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,500°C2,732 °F

Liquidus Temperature

1,483°C2,701 °F
1,525°C2,777 °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

42.6 W/m·K24.6 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.3 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)

425°C797 °F
300°C572 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8.6 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.62 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
60%

Weldability

40 / 100
85 / 100

Formability (cold)

40 / 100
62 / 100

Brazeability / Solderability

55 / 100
60 / 100

Polishability

60 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
26 MJ/kg11,178 BTU/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

88 kN·m/kg
62 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

562 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

12
9

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 scale4140HC380LA

Manufacturing and finishing

Capability4140HC380LA
CNC machiningYes—
Casting & forgingYes—
Default conditionHRCR
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

4140 vs HC380LA — frequently asked

Is 4140 stronger than HC380LA?

Yes. 4140 has a typical yield strength of 480 MPa (69.6 ksi) against 420 MPa (60.9 ksi) for HC380LA — about 14% more. Tensile strength is 690 MPa (100 ksi) vs 490 MPa (71.1 ksi).

Which is cheaper, 4140 or HC380LA?

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 is easier to machine, 4140 or HC380LA?

4140, by a small margin. Both rate good for machinability — 60/100 against 55/100 for HC380LA; for welding the order is HC380LA first (excellent, 85/100) then 4140 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4140 and HC380LA 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.