Aluminum alloys are widely used metal in various industries. they are lightweight and have good strength. There are many different types of aluminum alloys with different names in the market. how do you know which one is suitable for your project? whare are difference between each types? how they are named? in this blog, we will give you answers to these questions.
What is Aluminum alloy?Â
Aluminum alloy is mainly composed of pure aluminum, combines with other elements such as copper, silicon, magnesium and zinc to improve its properties. aluminum alloys are lightweight and have excellent corrosion resistance, good electrical and thermal conductivity.
Advantage of aluminum alloy for CNC machiningÂ
Machinability
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.
Lightweight
Aluminum alloy is lightweight, its density is 2.7 g/cmÂł 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.
Recyclability
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.
types of Aluminum alloyÂ
Wrought Aluminum AlloyÂ
Wrought aluminum alloys has a big portion of all kinds of aluminum alloys. they are divided into heat treatable and non-heat treatable alloys. they contain Copper, magnesium and zinc which provide their initial strength. Corresponding to series 2xxx, 6xxx, and 7xxx, Heat-treatable wrought aluminum alloys can be strengthened further through heat treatment. Non-Heat Treatable Aluminum Alloy is Corresponded to the 1xx, 3xx, and 5xx series of wrought alloys, it can be strengthened further through strain hardening or cold working.
Cast Aluminum Alloys
Cast aluminumalloys have a significant presence of silicon in its composition. they are created when aluminum is heated to extremely high temperatures. these alloys have a low tensile strength and can be used to create cost-efficient products.
How aluminum alloy named
When we see the name of aluminum alloys.you may wonder what is number and letter means, such as 6061, 6061-T6, 7075-T651. as below , we take an example of 6061-T6 to explain to you:
the first number “6″ represents the aluminum alloy group,its detail meaning as blow:
- Industrial pure aluminum,
- Aluminum-copper series alloy,
- Aluminum-manganese series alloy,
- Aluminum-silicon series alloy,
- Aluminum-magnesium series alloy,
- Aluminum-magnesium-silicon series alloy,
- Aluminum-zinc-magnesium-copper series alloy,
- Other alloys,
the second numbder “0” Indicates the control of alloying elements or impurities’ maximum content as below:
- 0: Original alloy, indicating no special control over impurity maximum content,
- 1-9: Modified alloy, indicating special control over one or more individual impurities or alloying element maximum content.
the numbder “61″ represents a kind of alloys within the same group. the rest letter’s meaning as blow:
T6: Represents the base status code.
F: As-fabricated condition, suitable for products that do not require special hardening or heat treatment process during the forming process.
O: Annealed condition, results in a material that is more easily machined, tougher, and more ductile. It can be followed by a single-digit Arabic numeral except 0.
H: Strain-hardened condition, suitable for products made from non-heat-treatable aluminum alloys in series 1, 3, 5, etc., where strength is increased by strain hardening.
W: Solution heat-treated condition, an unstable condition applicable only to alloys that are naturally aged at room temperature after solution heat treatment.
T: Heat-treated condition, suitable for products made from heat-treatable aluminum alloys in series 2, 6, 7, etc., where the product reaches a stable state after heat treatment.
Aluminum SERIES
The Aluminum Association Inc. has approved over 400 wrought aluminum alloys. These alloys are categorized using the four-digit Wrought Alloy numbders, which are considered as properties such as thermal response, mechanical treatment, and primary alloy element.
Common aluminum alloys for CNC machining

Aluminum 6061 VS 7075: Definition and Differences
Common Aluminum alloys for EXTURSION
Aluminum alloys from the 6xxx series are particularly suitable for extrusion processes, and three specific alloys commonly find applications in extrusion:
Common Aluminum alloys for CASTING
Aluminum alloys for die casting have several types like aluminum-silicon, aluminum-copper, aluminum-magnesium, aluminum-zinc and more. The common grades for die-casting aluminum alloys are defined by the standards of Japan’s JIS and ANSI. The table below shows common die-casting grade series under various standards.
casting aluminum alloy type | ANSI | SAE J452 | JIS | DIN | GB |
AI-Si-Mg | 360 | 309 | n/a | n/a | YL104 |
A360 | 309 | ADC3 | AlSi10Mg (Fe) | YL101 | |
AI-Si-Cu | A380 | 306 | ADC10 | AlSi8Cu3Fe | YL112 |
A383 | 383 | ADC12 | AlSi12(Cu) | YL113 | |
A384 | 303 | ADC14 | AlSi12 | YL116 | |
AI-Si | A413 | 305 | ADC6 | AlSi10Mg | YL102 |
C443 | 304 | ADC7 | n/a | n/a | |
AI-Mg | 518 | n/a | ADC5 | AIMg9 | YL302 |
How to choose an Aluminum Grade?
before you chosse the aluminum, you will need to consider your machined parts requirement and the machining process you will use. some of general consideration as below:
Strength Requirements
from the above introduction of each aluminum alloy , you will find theire strength properties. Aluminum 7075 has the best strength among those.
Corrosion Resistance
Consider the environment in which your aluminum components will be exposed. Some aluminum alloys offer exceptional corrosion resistance like 5052 or 6061, known for their corrosion resistance.
Weldability
If your project requires welding, ensure that the chosen aluminum grade is weldable. aluminum 6061 is more weldable than 7075.
Machinability
if you will use aluminum alloy for CNC machining, it is better to choose the one easy to be machined. Aluminum 6061 has a good Machinability for machining.
Comparison table of Common aluminum alloy
Alloy Type | Recommended For | Weldability | Machinability | Corrosion Resistance | Strength |
Alloy 1100 | Metal Spinning | Easily | Good | Highly | Low |
Alloy 2024 | Aerospace Application | Challenging | Fair | Limited | High |
Alloy 3003 | Chemical Equipment | Easily | Good | Good | Medium |
Alloy 5052 | Marine Applications | Easily | Fair | Excellent | Medium |
Alloy 6061 | Structural Applications | Excellent | Good | Excellent | Medium |
Alloy 6063 | Architectural Applications | Easily | Fair | Good | Medium |
Alloy 7075 | Aerospace Applications | Challenging | Fair | Fair | High |
Conclusion
Using a proper Aluminum alloys for your products is the key for quality. you may need to choose a professional supplier who are capable of managing different types of aluminum alloys. KUSLA have rich experiences of aluminum machining services can help you for your projects. contact us today to get a instant quotation.