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Steel A3 vs SKD11

Steel · grade comparison

Steel A3 and SKD11 are both steel grades, both tool steel. SKD11 is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 430 MPa (62.4 ksi) for A3, about 16% more; tensile strength follows at 820 MPa (119 ksi) vs 760 MPa (110 ksi). In exchange, A3 is the more ductile: elongation 20% versus 12% for SKD11, and SKD11 is harder (20 HRC vs 19 HRC). SKD11 runs hotter in service (250°C vs 200°C continuous) and A3 conducts heat better (24 W/m·K vs 20 W/m·K).

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

SKD11Choose it when strength drives the design, or when the part sees heat.

A3 vs SKD11: properties

A3SKD11

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
80 GPa11.6 Msi

Tensile Strength (Ultimate)

760 MPa110 ksi
820 MPa119 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
500 MPa72.5 ksi

Elongation at Break

20%
12%

Reduction in Area

35%
20%

Shear Strength

460 MPa66.7 ksi
550 MPa79.8 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

217 HB
225 HB

Hardness, Rockwell B

96 HRB
98 HRB

Hardness, Rockwell C

19 HRC
20 HRC

Hardness, Vickers

228 HV
235 HV

Fatigue Strength (Endurance Limit)

—
380 MPa55.1 ksi

Fracture Toughness (K_IC)

—
30 MPa·√m27.3 ksi·√in

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 900 MPa131 ksi

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
1,420°C2,588 °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
10.9 µm/m·K6.1 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
250°C482 °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).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.35 V

Corrosion Resistance

16 / 100
25 / 100

Manufacturability

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

Machinability

38 / 100
32 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
30%

Weldability

15 / 100
20 / 100

Formability (cold)

20 / 100
25 / 100

Brazeability / Solderability

35 / 100
40 / 100

Polishability

70 / 100
80 / 100

Same in both: Castability 25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

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

Typical Recycled Content

30%
40%

Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
106 kN·m/kg

Specific Stiffness (E / density)

25.8 MN·m/kg
27.3 MN·m/kg

Modulus of Resilience

455 kJ/m³
595 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 scaleA3SKD11

Manufacturing and finishing

CapabilityA3SKD11
Default condition—Annealed
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

A3 vs SKD11 — frequently asked

Is SKD11 stronger than A3?

Yes. SKD11 has a typical yield strength of 500 MPa (72.5 ksi) against 430 MPa (62.4 ksi) for A3 — about 16% more. Tensile strength is 820 MPa (119 ksi) vs 760 MPa (110 ksi).

Which is cheaper, A3 or SKD11?

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 SKD11?

A3. Its machinability rates fair (38/100) against poor (32/100) for SKD11; for welding the order is SKD11 first (poor, 20/100) then A3 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A3 and SKD11 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.