CNC milling is widely used in Rapid prototyping and low volume manufacturing for both plastic and metal parts. aluminum almostly is the most widely used metal in CNC aluminum machining. in this blog, we wil share with you a guide about CNC milling aluminum.

What is CNC Milling?

CNC milling is one of CNC machining processes that use computer control system to rotate the cutting tools to gradually remove material from a workpiece. the workpiece is fixed on a linear moved table.

CNC milling TOOLS for Aluminum

YG cemented carbide tool and High-Speed Steel (HSS) Tools are two common CNC machine tools used a lot in aluminum milling process. YG cemented carbide can reduce the tool chemical reaction with aluminum alloy and High-Speed Steel (HSS) Tools is sharp for Finishing operations such as threading, contouring.



Aluminum alloys have excellent machinability, becasue it is a soft metal that can chip and shape easily. this menas it can be cut by CNC milling and CNC turning cutting tool easily. this kind of easy to be machined property can reduce much the machining time so that reduce the cost. and aslo reduce the risk of deformation so that improve much the precision and repeatability of the machined aluminum parts.

Corrosion Resistance

Aluminum alloy have high resistance to corrosion becasue aluminum naturely forms a thin oxide layer on its surface,which protects against chemical wear and oxidization. Different aluminum grades differ greatly in their resistance to corrosion becasue the additional elements amounts they have. The most corrosion-resistant grades is Alunminum 6061 which is widely used in the applications with corrosion environment.


Aluminum alloy is lightweight, its density is 2.7 g/cm³ which is one-third the density of steel. This lightweight contribute a lot in thoses application needs lower weight such as Auotomotive industry.

Electrical Conductivity

Aluminum alloys are usually found in Electrical components becasue aluminum have high electrical conductivity. Pure aluminum has an electrical conductivity of about 37.7 million siemens per meter at room temperature. In aluminum alloy, with other elements added, its conductivitie become lower but still much better than steels and other metals but not copper.

Strength-To-Weight Ratio

Even aluminum alloy are lightweight, but aluminum alloys still can provide excellent strength and structural integrity. that is why in automotive and aerospace industries, a lot of CNC-machined aluminum parts are used. the strength-to-weight ratio differ in different grades of aluminum alloy. 7075 is more strong than 6061, so it is used a lot in aerospace and marine applications.


Aluminum is highly recyclable, which is perfect for CNC machining , becasue CNC machining is a subtractive manufacturing method which means there is a relatively large amount of waste material in the form of chips from the cutting tool. In this way CNC machining applications can use recyclable materials to reduce the cost of machined parts.

7 Aluminum Grades for CNC Milling Machining

Aluminum 2024-T4 

Aluminum alloy 2024-T4 is primarily use is in the aerospace industry, including aircraft fuselages, transport vehicle components, and wing tension members.

Aluminum 5052 

Aluminum alloy 5052 have excellent corrosion resistance.It is often used in the marine industry, particularly in manufacturing marine equipment.

Aluminum 6061-T6 

Aluminum alloy 6061-T6 is widely used in CNC machining becasue of the good balance between strength and machinability. it is used in across various applications including chassis manufacturing, bicycle frames, valves and computer components.

Aluminum 6063 

Aluminum alloy 6063 has moderate strength and high ductility, making it suitable for mold forming.

Aluminum 6082

Aluminum alloy 6082 have higher tensile strength and corrosion resistance, it is Commonly used in construction for structures like bridges, towers and trusses.

Aluminum 7075-T6 

Aluminum alloy 7075-T6 have high strength and corrosion resistance, it is used in aerospace and military industry for components such as aircraft fittings, missile parts and fuses.

Aluminum MIC 6 

Aluminum alloy MIC 6 is good for for producing stable and high tolerance sheets. It offers an excellent balance of strength-to-weight ratios, precision, elasticity and thermal stability.

Key Challenges In Aluminum CNC Milling Machining

There are two main challenges for milling Aluminum due to the properties of aluminum itself.

  1. During the aluminum milling process, the aluminum chips with high temperature will be generated. these aluminum chips will affect the coating and cutting edge of the tool which result in increased tool wear and shortened life of the tool.
  2. Aluminum is easy to deform during high temperature caused by high speed cutting, this will affect the accuracy of final machined aluminum parts.

6 tips for CNC Milling Aluminum

Choose the right Cutting tools

Choose a larger rake angle cutting tool as much as possible to increase the chip space and reduce the sticking phenomenon.

Choose the right type of Aluninum alloy

There are so many types of aluminum alloys with different mechanical properties and machinability. Different aluminum grades with different machining parameters and will result in different finishes on the work part.

Cutting Speeds and Feeds

Use higher cutting speed and reduced feed rates for milling your aluminum products. This is because Too slow feed and speed may impair the tool’s cutting action and would just cause rubbing between the part and the tool.

Coolant and Lubrication

Aluminum generates high temperatures during CNC milling process, so to control the temperatue, lubricating aluminum and cooling aluminum is very important especially for extremely precise operations. Use a high quality cooling lubricant solution to dissipate the heat and increase part surface quality.

watch tool wear

A dull cutting tool may cause a bad surface finish because it does not cut the material with the desired quality, and also it will increase heat generation and machining times. Replace the end mill in time to achieve optimum results.

Secure Clamping rigidly

aluminum workpiece need to be clamped rigidly. becasue if not, this will cause undesired shifts in the workpiece while milling. The rigid clamping of the workpiece will result in a high percision and good surface finish.

Keep Saftey

Always wear safety glasses and hearing protection during aluminum processing for your saftety. Aluminum chips can fly around when milling aluminum, so you need to well protect yourself.

Applications Of Aluminum CNC milled Parts

Aerospace industry

Aerospace industry need lightweight, high precision components. CNC machining aluminum can fit this requirement well because aluminum is a lightweight metal compare with others. CNC milling can get high precision parts due to automatic control. aluminum 7075 is widely use in Aerospace industry for fittings of aircraft.

automotive industry

Another industry use a lot of CNC machined parts is the automotive industry. the cars request lightweight and strong parts to save energy. CNC milled aluminum parts are commonly used for engine components and structural components.

medical industry

CNC milled aluminum parts are also used in in the medical industry.Aluminum is a biocompatible material that can be sterilized, making it suitable for medical implants and devices. CNC milling aluminum can provide the high precision which required by the medical devices and also custom parts for different patient.


CNC aluminum machining are widely used in many applications, if you have any complex parts and also request high precision, welcome to contact KUSLA. We provide professional CNC machining services with many years experienced in the production of metal parts and prototypes especially in CNC aluminum machining service. Contact us to start your project today!

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