Aluminum 4145 vs 4643
Aluminum · grade comparison
Aluminum 4145 and 4643 are both aluminum grades, both heat resistant al. 4145 is the stronger of the two: yield strength 110 MPa (16 ksi) against 70 MPa (10.2 ksi) for 4643, about 57% more; tensile strength follows at 205 MPa (29.7 ksi) vs 165 MPa (23.9 ksi). In exchange, 4643 is the more ductile: elongation 15% versus 8% for 4145, and 4145 is harder (60 HB vs 45 HB). 4643 conducts heat better (160 W/m·K vs 130 W/m·K). On the shop floor, 4643 welds better (excellent vs fair).
4145Choose it when strength drives the design.
4643Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
4145 vs 4643: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 880 J/kg·K0.21 BTU/lb·°F · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Castability 80 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 4145 | 4643 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 16 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), DLC, E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating and 4 more.
4145 vs 4643 — frequently asked
Is 4145 stronger than 4643?
Yes. 4145 has a typical yield strength of 110 MPa (16 ksi) against 70 MPa (10.2 ksi) for 4643 — about 57% more. Tensile strength is 205 MPa (29.7 ksi) vs 165 MPa (23.9 ksi).
Which is cheaper, 4145 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, 4145 or 4643?
4145, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for 4643; for welding the order is 4643 first (excellent, 96/100) then 4145 (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 4145 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.