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Steel A3 vs L3

Steel · grade comparison

Steel A3 and L3 are both steel grades. Both yield at about 430 MPa — strength does not separate them. L3 is the more ductile: elongation 25% versus 20% for A3, and A3 is harder (217 HB vs 197 HB). L3 conducts heat better (38 W/m·K vs 24 W/m·K). On the shop floor, L3 machines more easily (good vs fair).

L3Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

A3 vs L3: properties

A3L3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

203 GPa29.4 Msi
207 GPa30 Msi

Shear Modulus

79 GPa11.5 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

760 MPa110 ksi
730 MPa106 ksi

Elongation at Break

20%
25%

Reduction in Area

35%
50%

Compressive Strength

900 MPa131 ksi
450 MPa65.3 ksi

Shear Strength

460 MPa66.7 ksi
480 MPa69.6 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

217 HB
197 HB

Hardness, Rockwell B

96 HRB
92 HRB

Hardness, Rockwell C

19 HRC
—

Hardness, Vickers

228 HV
207 HV

Fatigue Strength (Endurance Limit)

—
340 MPa49.3 ksi

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 430 MPa62.4 ksi

Physical

Density and transition temperatures.

Density

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

Same in both: Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,470°C2,678 °F

Thermal

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

Thermal Conductivity

24 W/m·K13.9 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

10.7 µm/m·K5.9 µin/in·°F
11.5 µm/m·K6.4 µin/in·°F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 200°C392 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.7 % IACS
8 % IACS

Electrical Resistivity

6.5×10⁻⁷ Ω·m25.6 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.62 V

Corrosion Resistance

16 / 100
12 / 100

Manufacturability

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

Machinability

38 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
60%

Formability (cold)

20 / 100
35 / 100

Brazeability / Solderability

35 / 100
45 / 100

Polishability

70 / 100
75 / 100

Same in both: Weldability 15 / 100 · Castability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

36 MJ/kg15,477 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.6 kg CO₂/kg
2.5 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
70 L/kg8.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
93 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

455 kJ/m³
447 kJ/m³

Thermal Diffusivity

6.6 mm²/s
10.5 mm²/s

Thermal Shock Resistance Index

8
12

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 scaleA3L3

Manufacturing and finishing

CapabilityA3L3
CNC machiningYes—
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

A3 vs L3 — frequently asked

What is the difference between A3 and L3?

Steel A3 and L3 are both steel grades. Both yield at about 430 MPa — strength does not separate them. L3 is the more ductile: elongation 25% versus 20% for A3, and A3 is harder (217 HB vs 197 HB).

Which is cheaper, A3 or L3?

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

Which is easier to machine, A3 or L3?

L3. Its machinability rates good (55/100) against fair (38/100) for A3.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A3 and L3 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.