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In the UK signage industry, the aluminium alloy used for sign channels and posts has a direct impact on the performance, safety, and longevity of the finished sign. The two most widely used alloys are 6063-T6 and 6005A-T6 . Though they may appear similar, their mechanical properties and real-world performance differ significantly.
At Sign Trade Supplies, we have committed to using 6005A-T6 for all our sign channels and posts. Here's why.
Why Alloy Choice Is Critical
Signs are exposed to physical stress during installation, environmental conditions such as wind and rain, and long-term wear. Choosing the right aluminium alloy can prevent problems such as:
Flexing or bending under wind load
Deformation or failure at bolt fixing points
Reduced lifespan due to structural fatigue
Both 6063-T6 and 6005A-T6 offer excellent corrosion resistance and can be finished to a high visual standard, but 6005A-T6 stands out for its superior strength and rigidity.
Comparing 6063-T6 and 6005A-T6
| Property | 6063-T6 | 6005A-T6 |
|---|---|---|
| Yield Strength (MPa) | ~170 | ~225 |
| Tensile Strength (MPa) | ~215 | ~270 |
| Hardness (Brinell) | ~75 | ~90 |
| Rigidity | Lower (more flexible) | Significantly greater |
| Extrudability | Excellent | More difficult |
| Surface Finish | Very Smooth | Smooth with Proper Equipment |
| Corrosion Resistance | Excellent | Excellent |
| Typical Usage | Decorative or small sign systems | High-strength structural signage |
6063-T6: Lightweight and Versatile
6063-T6 is commonly used in architectural and decorative applications. It's easy to extrude, supports thin-walled or complex shapes, and produces a smooth, high-quality surface finish. This makes it ideal for small to medium-sized signs or components where high loads are not expected.
However, its lower strength can present limitations. In thin-walled sign channels, 6063 may deform when installation bolts are over-tightened—particularly with square-headed bolts used alongside M8 nuts. This can cause the bolt to spin or tear through the channel wall, compromising the fixing point.
6005A-T6: Strength Where It Matters
6005A-T6 is a higher-strength alloy that resists deformation and delivers greater performance under mechanical stress. For installers and sign engineers, this translates to:
Greater rigidity during bolt tightening
Superior wind load resistance in post and panel signs
Improved durability under long-term outdoor exposure
In real-world conditions, 6005A T6 profiles maintain their shape better during installation, especially when torque is applied to square-headed bolts. Sign channels remain intact, and posts stay straight and steady even in challenging weather conditions.
Rigidity and Wind Load Resistance
A sign post or panel extrusion made from 6005A T6 is far more resistant to wind-induced bending than one made from 6063. Over time, wind pressure on a 6063 post may lead to flexing or leaning, while 6005A retains its shape and provides reliable support.
This rigidity also protects the visual integrity of the sign. For larger signage projects—particularly roadside or commercial panel signs—using 6005A T6 results in safer, longer-lasting installations.
Manufacturing Challenges and Solutions
6005A T6 is slightly more difficult to extrude and requires greater care during finishing. Achieving a consistent surface finish demands specialized tooling and production techniques. However, at Sign Trade Supplies, our facilities are equipped to handle these requirements.
With the right equipment and processes in place, we produce 6005A extrusions that match or exceed the finish quality of 6063, ensuring our customers receive both performance and appearance benefits.
On-Site Installation Advantages
For sign installers, the advantages of 6005A-T6 are clear:
Channels resist crushing under bolt torque
Square bolts stay firmly in place without damaging the profile
Posts remain upright and rigid in high winds or over time
These benefits reduce the risk of installation failures, improve customer satisfaction, and lower the likelihood of costly rework or maintenance.
Why Sign Trade Supplies Uses 6005A T6 as Standard
We believe in offering sign makers the strongest, most reliable materials available. That’s why:
All Sign Trade Supplies sign channels and posts are made from 6005A-T6
Our extrusions deliver maximum strength without sacrificing surface quality
Installers benefit from secure, long-lasting fixings and superior resistance to environmental stress
Conclusion: Making the Right Material Choice
6063-T6 remains popular in the industry due to its ease of manufacturing and high-quality finish. But when performance truly matters—particularly for structural or high-load sign systems— 6005A-T6 is the superior option .
By choosing 6005A T6 across our product range, Sign Trade Supplies ensures your signs stay stronger, last longer, and maintain their integrity , regardless of the environment or application.