6063-T5 vs 6063-T6 Aluminum: Heat Treatment and Property Comparison
In the previous article, we introduced the wrought aluminum alloy designation system. As is well known, the physical and mechanical properties of aluminum alloys are strongly affected by processing and heat treatment, with heat treatment playing a decisive role in final performance.
Wrought aluminum alloys are commonly marked with a temper designation, such as T5 or T6. This combination of the letter T and numbers indicates the specific heat treatment process applied to achieve the listed properties. A standardized system exists for these designations. The most common aluminum temper codes include F, O, H, W, and T, among which H and T tempers are the most widely used.
In this article, GNEE focuses on a detailed comparison of 6063-T5 and 6063-T6 aluminum alloys.
Aluminum Alloy Temper Designations (T Temper)
Aluminum alloy datasheets typically include a temper designation, which explains how the alloy was treated to obtain its mechanical properties.
Common T Temper Definitions for Aluminum Alloys
T1: Cooled from an elevated temperature and naturally aged
T2: Cooled from an elevated temperature, cold worked, and naturally aged
T3: Solution heat treated, cold worked, and naturally aged
T4: Solution heat treated and naturally aged to a stable condition
T5: Cooled from an elevated-temperature shaping process and artificially aged
T6: Solution heat treated and artificially aged
T7: Solution heat treated and stabilized
T8: Solution heat treated, cold worked, then artificially aged
T9: Solution heat treated, artificially aged, then cold worked
T10: Cooled from an elevated temperature, artificially aged, then cold worked
TX51 / TX511 / TX52: Solution heat treated and stress relieved by stretching or compression
6063-T5 Aluminum: Heat Treatment Characteristics
6063-T5 aluminum is produced by cooling from a high-temperature shaping process followed by artificial aging. It is suitable for aluminum products that undergo hot forming and then aging, without cold working. Minor straightening or leveling is allowed and does not significantly affect mechanical performance.
This temper is widely used for extruded profiles where good strength and excellent surface quality are required.
6063-T6 Aluminum: Heat Treatment Characteristics
6063-T6 aluminum undergoes solution heat treatment followed by artificial aging. Like T5, it is intended for products formed at elevated temperatures without cold working, and limited straightening or leveling does not reduce its mechanical limits.
Compared with T5, the T6 temper delivers higher strength and hardness, making it more suitable for applications with increased mechanical demands.
Mechanical Properties: 6063-T5 vs 6063-T6 Aluminum
Different heat treatment conditions result in noticeable differences in mechanical performance.
Typical Mechanical Property Comparison
6063-T5 Aluminum
Tensile Strength: ~160 MPa
Yield Strength: ~110 MPa
Hardness: ≥8.5 HW
Elongation: ~8%
6063-T6 Aluminum
Tensile Strength: ~205 MPa
Yield Strength: ~180 MPa
Hardness: ≥11.5 HW
Elongation: ~8%
Heat Treatment Process Differences Between 6063-T5 and 6063-T6
In some cases, 6063-T5 can approach the mechanical performance of 6063-T6 depending on aging parameters.
6063-T5 example:
Aging temperature around 205 °C, aging time approximately 1 hour
6063-T6 example:
Solution heat treatment at 515–525 °C, followed by water quenching (below 35 °C), then artificial aging above 175 °C for about 8 hours
These process differences explain why T6 typically achieves higher strength and hardness.
Applications of 6063-T5 and 6063-T6 Aluminum
Both 6063-T5 and 6063-T6 aluminum alloys are widely used in:
Aerospace and aviation components
Communication equipment
Automated machinery parts
Mold and tooling manufacturing
Electronics and precision instruments
SMT fixtures and PCB solder carriers
Although the two tempers differ in definition and mechanical properties, the overall performance difference for many 6063 aluminum products is relatively small.
6063-T5 vs 6063-T6: Selection Guidance from GNEE
Choose 6063-T5 aluminum when standard strength requirements are sufficient and cost efficiency or processing flexibility is preferred
Choose 6063-T6 aluminum when higher strength and hardness are required
Key Takeaway
For most applications, 6063-T5 can meet basic performance needs, while 6063-T6 is the better option for higher mechanical requirements.
At GNEE, we supply 6063 aluminum profiles in both T5 and T6 tempers, helping customers select the optimal solution based on performance, processing, and application needs.
