6061 vs 6063 Aluminum: What is the difference?

Last time, we analyzed the difference between 5052 and 6061, today we will analyze another common aluminum alloy: 6063. Aluminum 6061 and aluminum 6063 are popular alloys of aluminum that offer a wide range of benefits for manufacturing industries. These two aluminum alloy grades fall into the 6xxxx series of aluminum alloys. Since the aluminum 6061 and 6063 come from the 6xxxx series they share similar elemental composition and mechanical properties. Due to this, it may be very difficult for manufactures to differentiate between the two alloys.

There is however a need to use their respective characteristics to differentiate each alloy for usage purposes. With this, it is much easier to use the best alloy for one’s project. The main objective of this article is to help our readers to differentiate 6061 aluminum from 6063 aluminum.

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Basic Introduction To 6061 Aluminum & 6063 Aluminum

The 6061 aluminum and 6063 are impressive aluminum alloy in their respective domain. They share almost all properties the 6xxx aluminum series possess. Both are grades of aluminum alloy used for extrusion. Before we go into solving the question of “How does one choose one?”, We will examine each series respectively.

6061 Aluminum Grade

The aluminum 6061 is a member of the aluminum alloy 6000 series. It has a significant amount of both magnesium and silicon in its composition. This alloy is primarily formulated for wrought products. For the benefit of different regions, 6061 aluminum is designated as EN AW-6061 in European standards. Also, the 6061 aluminum in the AFNOR (French) designation is A-G1SUC while it is CSA GS11N in older literature.

The 6061 aluminum has been in the market since 1935 and it receives its standard designation in 1954. It is one of the most versatile heat-treatable alloys with a range of elemental alloy composition. 6061 aluminum is common for multi-purpose uses as it combines strength with corrosion resistance and highly weldable. It is found in different applications ranging from the aviation industry, marine, to automotive industries.

6063 Aluminum Grade

Aluminum 6063 is a member of the 6000 series of aluminum alloy. It is often referred to as architectural aluminum because it’s a top choice for architectural materials. The aluminum 6063 is designated H9 in British Standard (BS) and EN AW-6063 in European standards. The EN chemical designation for 6063 aluminum is AlMg0,7Si.

Aluminum 6061 has been in the market since 1944 and has received its standard designation in 1954. The 6063 aluminum is widely used to draw constant cross-sectional shapes because of its excellent response to extrusion. Examples of such shapes include tubing, bars, and many more. It is known for its high corrosion resistance property with a good surface finish. Its major elemental composition includes Al, Mg, and Si in descending order of quantity. While aluminum 6063 does not differ from aluminum 6061, its better corrosion resistance and lower strength make it a better choice for extrusion.

What Differentiates Between Aluminum 6061 and Aluminum 6063?

6061 aluminum and 6063 aluminum alloys are from the same series and may therefore share similar properties. As a result, it may be tricky to differentiate between 6061 aluminum and 6063 aluminum. Irrespective of how tricky it may be, their distinct properties can be used to draw comparisons between the two. To help our readers in deciding between the two alloys, the following attributes will be used to draw comparisons:

COMPARISON - 1

6061 vs 6063 Aluminum: Alloy Series

The 6061 aluminum and 6063 aluminum exist in different forms. Although both alloys come from the series 6000 alloys, they retain distinct properties. These distinct properties can be used to draw comparisons. In this section, we will differentiate 6061 aluminum from 6063 aluminum by listing out their respective alloy variations.

The 6061 aluminum alloy exists in pre-tempered and tempered grade. They include:

6061-O Aluminum
6061-T1 Aluminum
6061-T4 Aluminum
6061-T42 Aluminum
6061-T451 Aluminum
6061-T4510 Aluminum
6061-T4511 Aluminum
6061-T51 Aluminum
6061-T6 Aluminum
6061-T62 Aluminum
6061-T651 Aluminum
6061-T6510 Aluminum
6061-T6511 Aluminum
6061-T652 Aluminum
6061-T89 Aluminum
6061-T94 Aluminum

The 6063 aluminum exists in about 13 alloy variations. They include:

6063-0 Aluminum
6063-T1
6063-T4
6063-T42
6063-T5
6063-T52
6063-T6
6063-T62
6063-T66
6063-T8
6063-T83
6063-T831
6063-T832

COMPARISON - 2

6061 vs 6063 Aluminum: Chemical Components

Chemical components of both alloys can be used to draw comparisons. These chemical compositions may be the same, but the percentage composition differs.

The table below presents a summary of the alloy composition of 6061 aluminum and 6063 aluminum.

Element	6061 Aluminum	6063 Aluminum
Aluminum	95.85 – 97.70 %	97.50 – 99.40 %
Silicon	0.40 – 0.80 %	0.20 – 0.60 %
Zinc	0.00 – 0.25 %	0.00 – 0.10 %
Magnesium	0.80 – 1.20 %	0.45 – 0.90 %
Manganese (Mn)	0.00 – 0.15 %	0.00 – 0.10 %
Chromium	0.04 – 0.35 %	0.00 – 0.10 %
Copper	0.15 – 0.40 %	0.00 – 0.10 %
Iron (Fe)	0.00 – 0.70 %	0.00 – 0.35 %
Titanium (Ti)	0.00 – 0.15 %	0.00 – 0.10 %
Residuals	0.00 – 0.15 %	0.00 – 0.15 %

COMPARISON - 3

6061 vs 6063 Aluminum: Mechanical Properties

This involves the physical properties a material has. In this case, the two alloys are from the same series (aluminum 6000). It will be much easier to differentiate each alloy by examining their physical properties. The following properties will be used to draw out comparisons between the two alloys:

Machinability
Material Hardness
Overall Strength of Material

Machinability

This is a measure of how a material performs when machined such as being milled, turned, die-casted, and many more. We used qualitative measures to grasp the overall response to machining. The measure of their respective machinability is in form of a Likert scale which includes poor, fair, good, and excellent. Our examination reveals that 6061 aluminum is better machined compared to 6063. The 6061 is preferred over 6063 aluminum if machinability is the major concern of the proposed project. 6063 aluminum is also machinable but it is well known as an extrusion alloy.

Material Hardness

This is a measure of ductility, general material strength, and surface quality. Here, we used the Brinell scale which is a common measurement system for metals. It shows that based on metrics, 6061 aluminum and 6063 aluminum have Brinell hardness values of 95 and 73 respectively. It is important to know that the two alloys are strong and are ductile enough to be formed. However, the 6061 aluminum is preferable if the hardness is a major concern of a project.

Overall Strength of Material

The overall strength of a material is a combination of many factors. These factors include yield strength, ultimate strength, shear strength, fatigue strength, and many more. For your reference, we’ve come up with empirical metrics to show the exact strength of both alloys for comparison purposes. Overall, 6061 aluminum possesses higher metrics and may be preferred over 6063 aluminum. For more information refer to the mechanical properties summary table.

The Mechanical Properties Summary Table

Properties	6061 Aluminum	6063 Aluminum
Units	Metric	Metric
Shear Modulus	25.9 Gpa	26.0 Gpa
Modulus of Elasticty	70.3 Gpa	68.0 Gpa
Fatigue Strength	58 – 110 Mpa	39 – 95 Mpa
Shear Strength	84 – 210 MPa	70 – 190 MPa
Tensile Yield Strength	76 – 370 MPa	49 – 270 MPa
Ultimate Strength	310 MPa	241 MPa
Thermal Conductivity	167 W/m-K	190 – 220 W/m-K
Hardness	95	73
Machinability	Good	Fair
Surface Quality	Fair	Good
Extrudability	Good	Great
Workability	Fair	Good
Weldability	Good	Good

COMPARISON - 4

6061 vs 6063 Aluminum: Corrosion Resistance Comparison

When it comes to corrosion, both alloys are somewhat resistant to corrosion. When used, both alloys form a protective layer of oxide that makes them inert toward environmental bodies. However, 6063 aluminum is more resistant to corrosion compared to 6061 aluminum. This can be attributed to lesser copper composition – an elemental composite that increases materials susceptibility to corrosion.

COMPARISON - 5

6061 vs 6063 Aluminum: Common Applications Comparison

6061 Aluminum Application

Aluminum 6061 is widely used in the industries for general purposes because of its weldability and formability. As a matter of fact, its corrosion resistance and high strength have given 6061 aluminum its application in architectural, structural, and motor vehicle industries. 6061 aluminum uses are exhaustive, while its major applications include:

Aircraft and truck frames
Chemical equipment
Electronic parts
Fasteners
Furniture
Heat Exchangers
Electrical fittings
Heat Sinks
Marine frames
Welded assemblies

6063 Aluminum Application

Aluminum 6063 is generally used in extrusion projects as a result of its weldability, good workability, and moderate strength. Consequently, aluminum 6063 is regarded as “architectural aluminum” because of the combination of its strength, weldability, and workability. 6063 aluminum has a wide variety of applications among which include:

Architectural products
Building & construction extrusions
Furniture
General extrusions for medical, automotive, parts profiling, and more
Piping
Recreational equipment
Tubing

F.A.Q

6061 vs 6063: Which alloy is easier to machining?

In terms of machinability, it is evident that aluminum 6061 is more machinable compared to 6063 aluminum. The 6063 is also machinable but it is known as an extrusion alloy rather than machinability.

6061 vs 6063: Which alloy is harder?

When considering the hardness of both alloys, the ductility, surface quality, and the general strength of both materials are considered. It is however great that these qualities are scalable and can be measure using different scales. Based on these scales we discovered that the 6061 aluminum is the hardest compared to the 6063 aluminum. Hence, the reason for the preference given to 6061 aluminum over 6063 aluminum when hardness becomes a major concern.

6061 vs 6063: Which alloy is more expensive?

Cost is also an important comparison factor to differentiate both alloys from one another. We examined both alloy’s extruded parts from a cost standpoint. We discovered that 6063 aluminum extruded in a solid shape is the most cost-effective way to approach an aluminum extruded part.

6061 vs 6063: Which alloy is stronger?

When talking about stronger materials, many factors are considered. Such factors include ultimate strength, fatigue strength, bearing strength, hardness, yield strength, and many more. It can be shown in our mechanical properties summary table above that 6061 aluminum exhibited higher metrics. As a result, 6061 aluminum is perceived to be stronger than the 6063 aluminum, and it’s a perfect choice for projects that require strength.

6061 vs 6063: Which alloy is more resistant to corrosion?

In terms of corrosion resistance, the aluminum 6063 is preferred over the aluminum 6061. This is as a result of the less copper composition of 6063 aluminum. Copper is an elemental composite that increases materials' susceptibility to corrosion. If corrosion resistance is one of the major requirements for your project, then aluminum 6063 is a perfect choice.

6061 vs 6063. Can I improve the alloy’s mechanical properties?

In some cases, it is possible to increase the mechanical properties of an alloy. However, increasing the mechanical properties of an alloy has an impact on the ability to produce a thin, lightweight extrusion. Therefore, 6063 aluminum alloy, for example, allows from 25% up to 35% thinner walls than 6061 aluminum.

Summary: 6061 vs 6063, Which Aluminum Alloy is Better?

Finally, this blog post has been able to compare and contrast the 6061 aluminum and 6063 aluminum. It is however important to note that each of these aluminum alloy grades is best suited for specific projects. As a result, we cannot categorically state that one alloy is better than another. Also, the best alloy depends greatly on the project requirements. This means that, while one is better on a particular project, the other is also better on another project. Give us a call today if you have more questions or require the service of CNC machining 6061 or 6063 aluminum. Samples for testing are also available.