Pure aluminum melts at about 660.32 °C, 1220.58 °F, or 933.47 K at standard pressure. In rounded engineering tables, you will often see the value written as 660 °C.
That simple number is useful, but it is not the whole story. Commercial aluminum parts are usually made from alloys such as 6061, 6063, 6082, 5052, or 7075. These alloys may not melt at one exact temperature. They often have a melting range between the first solid phase that begins to melt and the point where the material is fully liquid.
Quick Answer: Aluminum Melting Point
| Material | Melting temperature |
|---|---|
| Pure aluminum | 660.32 °C |
| Pure aluminum | 1220.58 °F |
| Pure aluminum | 933.47 K |
| Broad aluminum alloy range | about 463-671 °C, depending on alloy chemistry |
The exact value depends on what you mean by “aluminum.” If you mean pure elemental aluminum, use 660.32 °C. If you mean a practical aluminum alloy, ask for the alloy grade and its solidus and liquidus temperatures.
Melting Point vs Melting Temperature
In everyday use, “melting point” and “melting temperature” are often used the same way. Both describe the temperature where a solid changes into a liquid.
For pure aluminum, a single number is reasonable because pure substances have a sharply defined phase-change temperature under a stated pressure. For alloys, the better wording is often melting range. An alloy can begin to soften or partially melt at one temperature and become fully liquid at a higher temperature.
This is why an alloy data sheet may list:
- Solidus: the temperature below which the alloy is fully solid.
- Liquidus: the temperature above which the alloy is fully liquid.
- Melting range: the temperature interval between solidus and liquidus.
The difference matters in casting, welding, brazing, heat treatment, and thermal failure analysis. A part does not need to reach the pure aluminum melting point before heat begins to affect strength, finish, or microstructure.
Why Aluminum Alloys Do Not Always Melt at One Temperature
Aluminum alloys contain magnesium, silicon, copper, zinc, manganese, chromium, and other elements in controlled amounts. Those elements improve strength, corrosion resistance, machinability, extrudability, or surface finish, but they also change the way the material behaves as temperature rises.
Instead of transforming from fully solid to fully liquid at one temperature, many alloys pass through a mixed region. Part of the material is solid, and part is liquid. In phase-diagram language, this region sits between the solidus and liquidus.
For a buyer or engineer, this means the right question is not only “What is the melting point of aluminum?” A better question is:
What is the melting range of the exact aluminum alloy and temper used in this part?
For example, 6063 is commonly used for aluminum extrusion because it forms complex profiles with good surface quality. 6061 is also widely used for extrusions and CNC machined parts where a stronger general-purpose alloy is needed. Their processing behavior is not identical, even though both belong to the 6000-series aluminum family.
Aluminum Melting Point Compared With Other Metals
| Metal | Approximate melting temperature |
|---|---|
| Zinc | 419.5 °C |
| Aluminum | 660 °C |
| Magnesium | 650 °C |
| Copper | 1084 °C |
| Carbon steel | about 1425-1540 °C |
| Stainless steel | about 1510 °C |
Aluminum melts at a much lower temperature than copper or steel. This is one reason aluminum is practical for casting, recycling, and some thermal manufacturing processes. It also means aluminum parts require careful evaluation in high-temperature environments, especially when strength, surface finish, or dimensional stability matters.
Lower melting temperature does not mean aluminum is weak in normal use. Aluminum alloys are widely used because they combine low density, corrosion resistance, formability, machinability, and useful strength-to-weight ratios.
Melting Point Is Not the Same as Service Temperature
The melting point tells you when the metal becomes liquid. It does not tell you the highest safe operating temperature for an aluminum part.
A part may become unsuitable long before it melts because of:
- loss of mechanical strength at elevated temperature;
- changes in heat-treated temper;
- thermal expansion and distortion;
- coating, anodizing, sealant, adhesive, or fastener limits;
- contact with another material that expands differently;
- fatigue, vibration, or load at temperature.
For example, an aluminum enclosure, rail, bracket, heat sink, or machine housing may never come close to 660 °C in use. Even so, temperature can still affect flatness, tolerances, surface treatment, and long-term reliability.
If your part is exposed to continuous heat, thermal cycling, or a nearby heat source, use melting point only as a basic reference. Design review should also include alloy, temper, load, finish, assembly method, and expected service environment.
Why Aluminum Extrusion Happens Below the Melting Point
Aluminum extrusion is not a melting process. In hot extrusion, the billet is heated enough to deform more easily, then forced through a die to create a continuous profile. General references place aluminum hot-extrusion temperatures below the melting point, often around the 300-600 °C range depending on the alloy and process conditions.
That distinction is important. If the billet were fully molten, it would no longer behave like a deformable solid being pushed through a die. Extrusion depends on controlled plastic deformation, not liquid flow.
For custom extruded profiles, melting temperature still matters indirectly. It helps engineers understand thermal margins, alloy behavior, and process windows. But extrusion feasibility depends more on profile geometry, alloy selection, die design, wall thickness, tolerance requirements, surface finish, and order volume.
Does the Oxide Layer Change Aluminum’s Melting Point?
Aluminum quickly forms a thin oxide layer when exposed to air. This layer is mainly aluminum oxide, which has a much higher melting point than aluminum metal.
In practical heating or melting, this oxide skin can affect surface behavior. It may remain as a film while the metal beneath softens or melts. That does not mean the aluminum bulk has a higher melting point. It means the surface oxide and the metal underneath are different materials.
This is one reason melting, welding, brazing, and surface preparation of aluminum require process control. Oxide, contamination, alloy chemistry, and heat input can all affect results.
Common Mistakes About Aluminum Melting Temperature
Mistake 1: Treating every aluminum alloy as pure aluminum
Pure aluminum melts at 660.32 °C. Aluminum alloys may melt over a range. Always confirm the grade.
Mistake 2: Using melting point as the service-temperature limit
A heat-exposed part can lose strength or dimensional stability far below the melting point. Check the application temperature, load, temper, finish, and assembly conditions.
Mistake 3: Assuming extrusion temperature means melting temperature
Hot extrusion uses elevated temperature, but it is still a solid-state forming process. The billet is heated below melting so it can deform through the die.
Mistake 4: Ignoring coatings and finishes
Anodizing, powder coating, adhesives, inserts, gaskets, and fasteners may have their own temperature limits. These limits can matter before the aluminum itself is at risk.
What to Confirm Before Choosing an Aluminum Alloy for Heat Exposure
If melting point is relevant to your project, collect these details before selecting an alloy or asking for a quote:
| Question | Why it matters |
|---|---|
| What alloy grade is required or preferred? | Different alloys have different melting ranges and process behavior. |
| What is the maximum service temperature? | Service temperature is usually far below melting point but can still affect performance. |
| Is the exposure continuous or short-term? | A brief thermal event and continuous operation create different risks. |
| Is the part load-bearing at temperature? | Strength reduction can matter before melting. |
| Is the part extruded, CNC machined, cast, welded, or assembled? | Process route changes alloy choice and thermal risk. |
| What surface finish is required? | Finish limits may govern the usable temperature. |
| Are tolerances or flatness critical? | Thermal expansion and distortion can affect fit. |
Manufacturing Note for Custom Aluminum Parts
For most readers searching “aluminum melting point,” the right answer is the temperature itself. For manufacturing teams, the next step is usually more specific: confirm the alloy, process route, surface treatment, and service environment.
Zheng Ji Aluminum supports custom aluminum projects that may combine extrusion, CNC machining, surface treatment, and supplementary fabrication. If your drawing includes heat exposure, alloy uncertainty, or finishing requirements, an engineering review can help decide whether melting range is actually the key risk or whether strength, temper, coating, tolerance, or assembly design matters more.
This is not necessary for every project. A simple non-thermal profile may only need normal alloy and drawing review. But for parts exposed to heat or thermal cycling, it is worth asking the question early.
FAQ
What is the melting point of aluminum in Celsius?
Pure aluminum melts at about 660.32 °C at standard pressure. Rounded engineering references often use 660 °C.
What is the melting point of aluminum in Fahrenheit?
Pure aluminum melts at about 1220.58 °F.
What is the melting point of aluminum in Kelvin?
Pure aluminum melts or freezes at about 933.47 K. The aluminum freezing point is one of the fixed points used in ITS-90 temperature calibration references.
Do aluminum alloys melt at the same temperature as pure aluminum?
No. Many aluminum alloys melt over a range. A broad engineering reference lists aluminum alloys at about 463-671 °C, but the useful value depends on the exact alloy.
Does aluminum extrusion melt the aluminum?
No. Hot extrusion heats aluminum so it can deform through a die, but the process is normally performed below the melting temperature.
Is melting point enough to judge a high-temperature aluminum part?
No. Also check alloy, temper, mechanical load, finish, thermal cycling, tolerance, and assembly conditions.
Source Notes for Editorial Review
- Melting-point exact value and ITS-90 context: https://en.wikipedia.org/wiki/Melting_points_of_the_elements_(data_page), https://en.wikipedia.org/wiki/International_Temperature_Scale_of_1990
- Engineering rounded values and alloy range: https://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html
- Solidus/liquidus concept: https://en.wikipedia.org/wiki/Liquidus_and_solidus
- Extrusion temperature/process distinction: https://en.wikipedia.org/wiki/Extrusion
- Aluminum oxide context: https://en.wikipedia.org/wiki/Aluminium
