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Steel 4023 vs 4140

Steel · grade comparison

Steel 4023 and 4140 are both steel grades. 4140 is the stronger of the two: tensile strength 690 MPa (100 ksi) against 552 MPa (80.1 ksi) for 4023, about 25% more. 4140 is the more ductile: elongation 22% versus 18% for 4023, and 4140 is harder (210 HB vs 163 HB). On the shop floor, 4023 welds better (very good vs fair) and 4023 sits in a lower cost tier (budget, $) than 4140 (standard, $$).

4023Choose it when it will be welded, or when cost is the deciding factor.

4140Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

4023 vs 4140: properties

40234140

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

552 MPa80.1 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

470 MPa68.2 ksi
480 MPa69.6 ksi

Elongation at Break

18%
22%

Shear Strength

360 MPa52.2 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
345 MPa50 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

163 HB
210 HB

Hardness, Rockwell B

84 HRB
94 HRB

Hardness, Vickers

171 HV
220 HV

Compressive Strength

—
480 MPa69.6 ksi

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 · Reduction in Area 50%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,416°C2,581 °F

Liquidus Temperature

1,500°C2,732 °F
1,483°C2,701 °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

43 W/m·K24.8 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · 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).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.61 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

65 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
62%

Weldability

74 / 100
40 / 100

Formability (cold)

50 / 100
40 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

55 / 100
60 / 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
2.2 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
55 L/kg6.6 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
88 kN·m/kg

Modulus of Resilience

539 kJ/m³
562 kJ/m³

Thermal Shock Resistance Index

9
12

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg · Thermal Diffusivity 11.5 mm²/s

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 scale41404023

Manufacturing and finishing

Capability40234140
CNC machining—Yes
Sheet metal—Yes
Casting & forging—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

4023 vs 4140 — frequently asked

Is 4140 stronger than 4023?

Yes. 4140 has a typical tensile strength of 690 MPa (100 ksi) against 552 MPa (80.1 ksi) for 4023 — about 25% more.

Which is cheaper, 4023 or 4140?

4023 is the lower-cost material: it sits in the budget tier ($) while 4140 is standard ($$). 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, 4023 or 4140?

4023, by a small margin. Both rate good for machinability — 65/100 against 60/100 for 4140; for welding the order is 4023 first (very good, 74/100) then 4140 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4023 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.