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Aluminum 4343 vs 4643

Aluminum · grade comparison

Aluminum 4343 and 4643 are both aluminum grades, both heat resistant al. 4643 is the stronger of the two: yield strength 70 MPa (10.2 ksi) against 55 MPa (7.98 ksi) for 4343, about 27% more; tensile strength follows at 165 MPa (23.9 ksi) vs 130 MPa (18.9 ksi). In exchange, 4343 is the more ductile: elongation 20% versus 15% for 4643, and 4643 is harder (45 HB vs 40 HB). 4343 conducts heat better (180 W/m·K vs 160 W/m·K). On the shop floor, 4643 welds better (excellent vs good).

4343Choose it when the part is bent, formed or impact-loaded.

4643Choose it when strength drives the design, or when it will be welded.

4343 vs 4643: properties

43434643

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

130 MPa18.9 ksi
165 MPa23.9 ksi

Yield Strength (0.2% offset)

55 MPa8 ksi
70 MPa10.2 ksi

Elongation at Break

20%
15%

Shear Strength

85 MPa12.3 ksi
105 MPa15.2 ksi

Hardness, Brinell

40 HB
45 HB

Same in both: Elastic (Young's) Modulus 69 GPa10 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 50 MPa7.3 ksi

Physical

Density and transition temperatures.

Density

2.68 g/cm³0.1 lb/in³
2.69 g/cm³0.1 lb/in³

Melting Point (Solidus)

577°C1,071 °F
574°C1,065 °F

Liquidus Temperature

613°C1,135 °F
632°C1,170 °F

Thermal

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

Thermal Conductivity

180 W/m·K104 BTU/hr·ft·°F
160 W/m·K92.4 BTU/hr·ft·°F

Specific Heat Capacity

900 J/kg·K0.21 BTU/lb·°F
880 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

21.6 µm/m·K12 µin/in·°F
22 µm/m·K12.2 µin/in·°F

Latent Heat of Fusion

395 J/g170 BTU/lb
400 J/g172 BTU/lb

Min Service Temperature

-269°C-452 °F
-196°C-321 °F

Same in both: Max Service Temperature (continuous) 150°C302 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

42 % IACS
41 % IACS

Electrical Resistivity

4.1×10⁻⁸ Ω·m1.61 µΩ·in
4.2×10⁻⁸ Ω·m1.65 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.81 V
-0.83 V

Same in both: Corrosion Resistance 62 / 100

Manufacturability

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

Machinability

32 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
35%

Weldability

55 / 100
96 / 100

Formability (cold)

60 / 100
72 / 100

Castability

75 / 100
80 / 100

Brazeability / Solderability

98 / 100
45 / 100

Same in both: Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12 kg CO₂/kg
12.5 kg CO₂/kg

Typical Recycled Content

25%
20%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Water 1,200 L/kg144 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

49 kN·m/kg
61 kN·m/kg

Modulus of Resilience

22 kJ/m³
36 kJ/m³

Thermal Diffusivity

74.6 mm²/s
67.6 mm²/s

Thermal Shock Resistance Index

16
17

Same in both: Specific Stiffness (E / density) 25.7 MN·m/kg

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 scale43434643

Manufacturing and finishing

Capability43434643
CNC machining—Yes
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall—0.5 mm
Best machined surface—Ra 0.8 µm
DLC—Yes

Both are offered for Sheet metal. They share 15 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating, PTFE Coating and 3 more.

4343 vs 4643 — frequently asked

Is 4643 stronger than 4343?

Yes. 4643 has a typical yield strength of 70 MPa (10.2 ksi) against 55 MPa (7.98 ksi) for 4343 — about 27% more. Tensile strength is 165 MPa (23.9 ksi) vs 130 MPa (18.9 ksi).

Which is cheaper, 4343 or 4643?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 4343 or 4643?

4643. Its machinability rates fair (40/100) against poor (32/100) for 4343; for welding the order is 4643 first (excellent, 96/100) then 4343 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4343 and 4643 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.