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Aluminum 2017A vs 2018

Aluminum · grade comparison

Aluminum 2017A and 2018 are both aluminum grades. 2018 is the stronger of the two: yield strength 315 MPa (45.7 ksi) against 260 MPa (37.7 ksi) for 2017A, about 21% more. In exchange, 2017A is the more ductile: elongation 14% versus 12% for 2018, and 2018 is harder (120 HB vs 110 HB). 2018 runs hotter in service (200°C vs 120°C continuous) and 2018 conducts heat better (154 W/m·K vs 134 W/m·K).

2017AChoose it when the part is bent, formed or impact-loaded.

2018Choose it when strength drives the design, or when the part sees heat.

2017A vs 2018: properties

2017A2018

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

72.5 GPa10.5 Msi
74 GPa10.7 Msi

Shear Modulus

27 GPa3.9 Msi
28 GPa4.1 Msi

Bulk Modulus

75 GPa10.9 Msi
76 GPa11 Msi

Tensile Strength (Ultimate)

410 MPa59.5 ksi
420 MPa60.9 ksi

Yield Strength (0.2% offset)

260 MPa37.7 ksi
315 MPa45.7 ksi

Elongation at Break

14%
12%

Compressive Strength

260 MPa37.7 ksi
320 MPa46.4 ksi

Shear Strength

260 MPa37.7 ksi
275 MPa39.9 ksi

Fatigue Strength (Endurance Limit)

125 MPa18.1 ksi
115 MPa16.7 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
22 MPa·√m20 ksi·√in

Hardness, Brinell

110 HB
120 HB

Hardness, Rockwell B

62 HRB
—

Hardness, Vickers

118 HV
128 HV

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.79 g/cm³0.1 lb/in³
2.8 g/cm³0.1 lb/in³

Melting Point (Solidus)

512°C954 °F
507°C945 °F

Liquidus Temperature

641°C1,186 °F
638°C1,180 °F

Thermal

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

Thermal Conductivity

134 W/m·K77.4 BTU/hr·ft·°F
154 W/m·K89 BTU/hr·ft·°F

Specific Heat Capacity

873 J/kg·K0.21 BTU/lb·°F
875 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

23 µm/m·K12.8 µin/in·°F
22.3 µm/m·K12.4 µin/in·°F

Max Service Temperature (continuous)

120°C248 °F
200°C392 °F

Same in both: Latent Heat of Fusion 390 J/g168 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

34 % IACS
40 % IACS

Electrical Resistivity

5.07×10⁻⁸ Ω·m2 µΩ·in
4.31×10⁻⁸ Ω·m1.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.69 V
-0.7 V

Corrosion Resistance

35 / 100
33 / 100

Manufacturability

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

Machinability

75 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

75%
—

Weldability

20 / 100
22 / 100

Formability (cold)

45 / 100
25 / 100

Castability

25 / 100
—

Polishability

55 / 100
50 / 100

Same in both: Brazeability / Solderability 15 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

1,100 L/kg132 gal/lb
1,200 L/kg144 gal/lb

Typical Recycled Content

25%
20%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

147 kN·m/kg
150 kN·m/kg

Specific Stiffness (E / density)

26 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

466 kJ/m³
670 kJ/m³

Thermal Diffusivity

55 mm²/s
62.9 mm²/s

Thermal Shock Resistance Index

33
39

Strength versus weight

Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scale2017A2018

Manufacturing and finishing

Capability2017A2018
CNC machiningYes—
Sheet metalYes—
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
DLCYes—
E-CoatingYes—
ElectropolishingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

2017A vs 2018 — frequently asked

Is 2018 stronger than 2017A?

Yes. 2018 has a typical yield strength of 315 MPa (45.7 ksi) against 260 MPa (37.7 ksi) for 2017A — about 21% more. Tensile strength is 420 MPa (60.9 ksi) vs 410 MPa (59.5 ksi).

Which is cheaper, 2017A or 2018?

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.

When should I choose 2017A over 2018?

Pick 2017A when the part is bent, formed or impact-loaded. Pick 2018 when strength drives the design, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 2017A and 2018 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.