What Temperature Does Aluminum Melt?

Aluminum is one of the most used metals in the world, but do you know what temperature it melts at? Whether you're casting, machining, or just curious-knowing this number matters.

Aluminum melts at around 660.3°C (1220.5°F), which makes it suitable for a wide range of industrial and home applications, from casting to CNC machining.

If you're working with aluminum-whether you're designing, machining, or melting-you need to understand how its melting point impacts every step. Let’s explore the full picture behind this key property of aluminum.

What Temperature Does Aluminum Melt?

Aluminum is everywhere-phones, laptops, cars, even spacecraft. But to form all these products, it first has to melt.

Pure aluminum melts at 660.3°C (1220.5°F), making it relatively easy to process compared to many other metals.

This temperature is lower than steel (which melts around 1370°C to 1510°C), meaning aluminum needs less energy to reach a molten state. That’s a big reason why it's widely used in manufacturing.

When I first started working with CNC machining for aluminum components, I had to quickly learn how its melting point influenced how fast we could remove material. Lower melting means we have to control heat during machining to avoid deformation or surface burns.

Comparison of Melting Points

This relatively low melting point allows aluminum to be easily cast and reshaped. But that same property also means overheating it during CNC machining can be a real risk-especially in high-speed operations.

How Does Aluminum’s Melting Point Affect Casting?

Casting aluminum is common because of its lightweight and formability. But that doesn’t mean it’s always easy.

Aluminum’s relatively low melting point makes it ideal for die casting, sand casting, and investment casting, but it also increases the risk of oxidation and shrinkage during solidification.

Casting aluminum alloys is a careful balance. When molten, aluminum easily reacts with air, forming oxides that can ruin surface quality and mechanical properties. That's why many casting shops use inert gas blankets or fluxes to protect the molten metal.

When I worked with a client from Germany on a batch of custom industrial brackets, we had to adjust the mold temperature and pour rate to reduce internal porosity. The aluminum started solidifying too quickly near the surface, trapping air inside.

Key Casting Considerations for Aluminum

If the casting temperature is too low, aluminum may not flow well into all the mold details. Too high, and you’ll face burn-in, gas porosity, and poor grain structure. Keeping the molten metal just above 700°C is usually a safe range.

What Temperature Do Aluminum Alloys Start Melting?

Not all aluminum melts at the same temperature-especially when alloyed with other elements like silicon, copper, or magnesium.

Most aluminum alloys start melting around 463°C (865°F) and fully melt by about 670°C (1238°F), depending on composition.

The melting range (solidus to liquidus) varies widely. For instance, 6061-T6 alloy starts softening at around 582°C and becomes fully liquid by about 652°C. This affects both heat treatment and casting processes.

Common Aluminum Alloys and Their Melting Ranges

Knowing the melting range helps avoid overheating during welding or post-processing. Once, during a thermal post-processing step for a medical device housing, I accidentally hit 650°C, thinking the alloy was stable. It warped beyond use. Lesson learned.

Is Aluminum’s Melting Point Ideal for CNC Machining?

CNC machining requires the right balance between hardness and heat tolerance. So where does aluminum stand?

Aluminum's relatively low melting point is a double-edged sword in CNC machining-it allows fast cutting but requires precise thermal control.

High-speed machining generates heat, and since aluminum melts at 660.3°C, chips and tool contact zones can get dangerously hot. If the tool isn’t sharp or properly cooled, the aluminum may melt slightly and weld onto the cutting tool.

When working on aluminum housings for a smart wearable device, I had to reduce spindle speeds and increase coolant flow. Otherwise, chip welding ruined surface quality and created tool marks.

Tips to Optimize CNC Machining for Aluminum

• Use sharp, carbide tools - aluminum is soft, but builds up quickly on dull tools
• Apply proper coolant - to dissipate heat and avoid chip welding
• Optimize feed and speed - go fast, but stay cool
• Clear chips constantly - built-up chips raise temperature

CNC aluminum machining is best when balancing high speed with cooling and chip evacuation. Its softness helps, but its low melting point can quickly become a problem without the right setup.

Can Aluminum Melt in a Home Furnace?

You don’t need a high-tech factory to melt aluminum-many hobbyists do it at home. But is it really feasible?

Yes, aluminum can melt in a home furnace or foundry setup, as long as it reaches at least 700°C (1292°F) for safe pouring.

Homemade foundries often use propane burners or charcoal with forced air (via hairdryers or fans). They’re cheap, and they work. I once helped a local makerspace build a DIY furnace from a steel bucket, refractory cement, and a simple propane torch. We reached 750°C and melted old soda cans and scrap brackets with no problem.

What You Need to Melt Aluminum at Home

However, safety is everything. Molten aluminum can cause severe burns. Always wear protective gear and work in a ventilated area. Never add wet metal into the crucible-it can cause explosive steam reactions.

Conclusion

Aluminum's melting point affects everything-from how we cast it, machine it, or even melt it at home. Knowing this number and how it changes with alloys helps you avoid costly mistakes and make better design decisions.