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Steel A2 vs SKD1

Steel · grade comparison

Steel A2 and SKD1 are both steel grades. SKD1 is the stronger of the two: tensile strength 780 MPa (113 ksi) against 740 MPa (107 ksi) for A2, about 5% more. In exchange, A2 is the more ductile: elongation 22% versus 12% for SKD1, and SKD1 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 (fair vs poor) and SKD1 sits in a lower cost tier (standard, $$) than A2 (premium, $$$).

A2Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SKD1Choose it when strength drives the design, or when cost is the deciding factor.

A2 vs SKD1: properties

A2SKD1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

203 GPa29.4 Msi
210 GPa30.5 Msi

Shear Modulus

78 GPa11.3 Msi
80 GPa11.6 Msi

Poisson's Ratio

0.28
0.29

Tensile Strength (Ultimate)

740 MPa107 ksi
780 MPa113 ksi

Yield Strength (0.2% offset)

470 MPa68.2 ksi
460 MPa66.7 ksi

Elongation at Break

22%
12%

Reduction in Area

45%
20%

Compressive Strength

500 MPa72.5 ksi
1,500 MPa218 ksi

Shear Strength

450 MPa65.3 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
350 MPa50.8 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

217 HB
235 HB

Hardness, Rockwell B

96 HRB
—

Hardness, Vickers

230 HV
245 HV

Fracture Toughness (K_IC)

—
16 MPa·√m14.6 ksi·√in

Hardness, Rockwell C

—
22 HRC

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
1,270°C2,318 °F

Liquidus Temperature

1,465°C2,669 °F
1,400°C2,552 °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
10.8 µm/m·K6 µin/in·°F

Max Service Temperature (continuous)

425°C797 °F
200°C392 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · 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).

Corrosion Resistance

20 / 100
25 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.4 V

Manufacturability

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

Machinability

45 / 100
28 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
27%

Weldability

20 / 100
15 / 100

Formability (cold)

35 / 100
10 / 100

Castability

20 / 100
25 / 100

Brazeability / Solderability

40 / 100
35 / 100

Polishability

70 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Water

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

Typical Recycled Content

35%
40%

Same in both: Embodied Carbon (primary production) 2.6 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

94 kN·m/kg
101 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
27.3 MN·m/kg

Modulus of Resilience

544 kJ/m³
504 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 scaleA2SKD1

Manufacturing and finishing

CapabilityA2SKD1
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 SKD1 — frequently asked

Is SKD1 stronger than A2?

Yes. SKD1 has a typical tensile strength of 780 MPa (113 ksi) against 740 MPa (107 ksi) for A2 — about 5% more.

Which is cheaper, A2 or SKD1?

SKD1 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 SKD1?

A2. Its machinability rates fair (45/100) against poor (28/100) for SKD1; for welding the order is A2 first (poor, 20/100) then SKD1 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A2 and SKD1 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.