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Steel A3 vs D6

Steel · grade comparison

Steel A3 and D6 are both steel grades. D6 is the stronger of the two: tensile strength 800 MPa (116 ksi) against 760 MPa (110 ksi) for A3, about 5% more. In exchange, A3 is the more ductile: elongation 20% versus 15% for D6, and D6 is harder (235 HB vs 217 HB). A3 conducts heat better (24 W/m·K vs 20 W/m·K). On the shop floor, D6 sits in a lower cost tier (standard, $$) than A3 (premium, $$$).

A3Choose it when the part is bent, formed or impact-loaded.

D6Choose it when strength drives the design, or when cost is the deciding factor.

A3 vs D6: properties

A3D6

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

203 GPa29.4 Msi
210 GPa30.5 Msi

Shear Modulus

79 GPa11.5 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

760 MPa110 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
450 MPa65.3 ksi

Elongation at Break

20%
15%

Reduction in Area

35%
28%

Compressive Strength

900 MPa131 ksi
—

Shear Strength

460 MPa66.7 ksi
520 MPa75.4 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

217 HB
235 HB

Hardness, Rockwell B

96 HRB
—

Hardness, Rockwell C

19 HRC
22 HRC

Hardness, Vickers

228 HV
245 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,420°C2,588 °F
1,250°C2,282 °F

Liquidus Temperature

1,470°C2,678 °F
1,400°C2,552 °F

Thermal

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

Thermal Conductivity

24 W/m·K13.9 BTU/hr·ft·°F
20 W/m·K11.6 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

250 J/g107 BTU/lb
—

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

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.5×10⁻⁷ Ω·m25.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.45 V

Corrosion Resistance

16 / 100
25 / 100

Manufacturability

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

Machinability

38 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
25%

Weldability

15 / 100
10 / 100

Formability (cold)

20 / 100
8 / 100

Castability

25 / 100
—

Brazeability / Solderability

35 / 100
30 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

36 MJ/kg15,477 BTU/lb
40 MJ/kg17,197 BTU/lb

Embodied Carbon (primary production)

2.6 kg CO₂/kg
2.9 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Typical Recycled Content

30%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
104 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
27.3 MN·m/kg

Modulus of Resilience

455 kJ/m³
482 kJ/m³

Thermal Diffusivity

6.6 mm²/s
5.6 mm²/s

Thermal Shock Resistance Index

8
7

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 scaleA3D6

Manufacturing and finishing

CapabilityA3D6
CNC machiningYes—
Default condition——
Relative cost$$$ Premium$$ Standard
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 D6 — frequently asked

Is D6 stronger than A3?

Yes. D6 has a typical tensile strength of 800 MPa (116 ksi) against 760 MPa (110 ksi) for A3 — about 5% more.

Which is cheaper, A3 or D6?

D6 is the lower-cost material: it sits in the standard tier ($$) while A3 is premium ($$$). 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, A3 or D6?

A3. Its machinability rates fair (38/100) against poor (30/100) for D6; for welding the order is A3 first (poor, 15/100) then D6 (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A3 and D6 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.