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Steel A2 vs D1

Steel · grade comparison

Steel A2 and D1 are both steel grades. A2 is the stronger of the two: yield strength 470 MPa (68.2 ksi) against 420 MPa (60.9 ksi) for D1, about 12% more. A2 is the more ductile: elongation 22% versus 16% for D1, and D1 is harder (235 HB vs 217 HB). A2 runs hotter in service (425°C vs 200°C continuous) and A2 conducts heat better (26 W/m·K vs 20 W/m·K). On the shop floor, A2 machines more easily (45 vs 35 out of 100) and D1 sits in a lower cost tier (standard, $$) than A2 (premium, $$$).

A2Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

D1Choose it when cost is the deciding factor.

A2 vs D1: properties

A2D1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

203 GPa29.4 Msi
207 GPa30 Msi

Shear Modulus

78 GPa11.3 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

740 MPa107 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

470 MPa68.2 ksi
420 MPa60.9 ksi

Elongation at Break

22%
16%

Reduction in Area

45%
30%

Compressive Strength

500 MPa72.5 ksi
900 MPa131 ksi

Shear Strength

450 MPa65.3 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
340 MPa49.3 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

217 HB
235 HB

Hardness, Rockwell B

96 HRB
99 HRB

Hardness, Vickers

230 HV
245 HV

Fracture Toughness (K_IC)

—
30 MPa·√m27.3 ksi·√in

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28

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
1,421°C2,590 °F

Liquidus Temperature

1,465°C2,669 °F
1,480°C2,696 °F

Thermal

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

Thermal Conductivity

26 W/m·K15 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
10.4 µm/m·K5.8 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

425°C797 °F
200°C392 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°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).

Corrosion Resistance

20 / 100
28 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.45 V

Manufacturability

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

Machinability

45 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

20 / 100
15 / 100

Formability (cold)

35 / 100
20 / 100

Castability

20 / 100
—

Brazeability / Solderability

40 / 100
35 / 100

Same in both: Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

36 MJ/kg15,477 BTU/lb
35 MJ/kg15,047 BTU/lb

Embodied Water

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

Same in both: Embodied Carbon (primary production) 2.6 kg CO₂/kg · Typical Recycled Content 35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

94 kN·m/kg
99 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
26.9 MN·m/kg

Modulus of Resilience

544 kJ/m³
426 kJ/m³

Thermal Diffusivity

7.2 mm²/s
5.6 mm²/s

Thermal Shock Resistance Index

9
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 scaleA2D1

Manufacturing and finishing

CapabilityA2D1
CNC machiningYes—
Default conditionAnnealed—
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.

A2 vs D1 — frequently asked

Is A2 stronger than D1?

Yes. A2 has a typical yield strength of 470 MPa (68.2 ksi) against 420 MPa (60.9 ksi) for D1 — about 12% more. Tensile strength is 740 MPa (107 ksi) vs 760 MPa (110 ksi).

Which is cheaper, A2 or D1?

D1 is the lower-cost material: it sits in the standard tier ($$) while A2 is premium ($$$). 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, A2 or D1?

A2, by a small margin. Both rate fair for machinability — 45/100 against 35/100 for D1; for welding the order is A2 first (poor, 20/100) then D1 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A2 and D1 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.