Aluminium Structure 290x290: Understanding Load Capacity
Aluminium Structure 290x290: What "Load Capacity" Really Means
For a professional buyer, the term "aluminium structure 290x290" refers to a family of truss with a square section measuring 290 mm x 290 mm. This dimension is a common standard for stage, exhibition and lighting support applications. But the real question is not the size: it is the load capacity (or load-bearing capacity), i.e. the mass that the structure can safely support depending on the span and the type of load.
This article explains how to read load tables, which parameters influence capacity, and how to compare the available models.
Materials and tubes: the basis of load capacity
The capacity of a truss depends first on its tubes and its alloy. The 290 mm models in our catalogue use a 6082/6061-T6 alloy. For example:
- WRF-29 Ladder Truss: main tube 50x3 mm, secondary tube 25x2 mm, diagonal 20x2 mm. Product page
- WRT-29 Triangle Truss: main tube 50x3 mm, secondary tube 30x2 mm, diagonal 20x2 mm. Product page
- WRS-29 Square Truss: main tube 50x3 mm, secondary tube 25x2 mm, diagonal 20x2 mm. Product page
- WRS-30 Square Truss: same tubes as the WRS-29. Product page
- WRS-40 Square Truss: main tube 50x3 mm, secondary tube 30x2 mm, diagonal 25x2 mm. Product page
- WRS-4060 Square Truss: main tube 50x3 mm, secondary tube 50x2 mm, diagonal 30x2 mm. Product page
The thicker the secondary tubes and diagonals, the more rigid the structure and the higher the load capacity. The WRS-4060, with its 50x2 mm secondary tubes and 30x2 mm diagonals, stands out clearly.
Reading a load table: span, distributed load and point load
A load table gives two values for each span:
- Distributed load (kg/m): mass distributed uniformly over the entire length.
- Point load (kg): mass concentrated at a single point (for example a motor or a projector).
The rule is simple: the greater the span, the lower the load capacity. It is a question of bending and buckling.
Concrete examples
WRF-29 Ladder Truss (ladder):
| Span (m) | Distributed load (kg/m) | Point load (kg) |
|---|---|---|
| 1 | 990 | 990 |
| 2 | 340 | 340 |
| 3 | 168 | 115 |
| 4 | 87 | 43 |
| 5 | 51 | 20 |
| 6 | 26 | 10 |
At 3 m, the distributed load is 168 kg/m, but the point load drops to 115 kg. At 5 m, it is only 51 kg/m and 20 kg point load. The WRF-29 is therefore suitable for short spans and light loads.
WRT-29 Triangle Truss:
| Span (m) | Distributed load (kg/m) | Point load (kg) |
|---|---|---|
| 3 | 371 | 557 |
| 4 | 250 | 500 |
| 5 | 139 | 348 |
| 6 | 109 | 327 |
| 7 | 85 | 298 |
| 8 | 67 | 268 |
The triangular shape offers better resistance to bending than a ladder. At 6 m, it still supports 109 kg/m distributed and 327 kg point loads.
WRS-29 and WRS-30 Square Truss (same values):
| Span (m) | Distributed load (kg/m) | Point load (kg) |
|---|---|---|
| 1 | 1942 | 1942 |
| 2 | 976 | 1899 |
| 3 | 658 | 1766 |
| 4 | 488 | 1466 |
| 5 | 392 | 1150 |
| 6 | 317 | 948 |
The square section is more versatile: it accepts higher loads and allows assemblies in several directions. At 4 m, there is still 488 kg/m and 1466 kg point loads available.
WRS-40 Square Truss:
| Span (m) | Distributed load (kg/m) | Point load (kg) |
|---|---|---|
| 3 | 936 | 718 |
| 4 | 732 | 680 |
| 5 | 465 | 644 |
| 6 | 320 | 612 |
| 7 | 232 | 585 |
| 8 | 176 | 560 |
WRS-4060 Square Truss:
| Span (m) | Distributed load (kg/m) | Point load (kg) |
|---|---|---|
| 4 | 805 | 1610 |
| 5 | 560 | 1400 |
| 6 | 403 | 1209 |
| 7 | 301 | 1054 |
| 8 | 247 | 988 |
| 9 | 210 | 945 |
The WRS-4060 is the most robust in the 290 mm range. At a 9 m span, it still supports 210 kg/m distributed and 945 kg point loads.
How to choose according to your application
- Short span, light load (set, small stand): WRF-29 or WRT-29.
- Medium span, moderate load (lighting, sound): WRS-29 or WRS-30.
- Long span or heavy load (stage structure, LED screen): WRS-40 or WRS-4060.
The type of load must also be taken into account: a high point load at mid-span is more critical than a distributed load. For dynamic loads (movement, wind), an additional safety margin is recommended.
Complementary structures: stage and floor
For a complete stage, truss alone is not enough. The Dance Floor (product page) is a dance floor with the following dimensions: straight edge 9150 mm x 100 mm x 22 mm, bias edge 1015 mm x 100 mm x 22 mm. The surface is treated anti-slip with a 45° bias edge, and the aluminium profiles are oxidised.
For large spans, the WR-PF05 Top-curved Structure Tent (product page) is a curved-roof tent structure. Main features: main profile in F27 aluminium alloy (6061/T6), roof pitch 18°, PVC-coated polyester fabric, white, weather-resistant, UV-resistant, B1 fire-retardant. Opaque roof ≥ 850 g/m², translucent walls ≥ 650 g/m². Spans range from 3.00 m to 30.00 m with side heights from 2.60 m to 4.00 m and ridge heights from 3.00 m to 8.60 m.
Buying advice
- Check the certificates: our structures are TÜV Rheinland tested and our factory is ISO 9001:2015 certified.
- Ask for the load tables: they must correspond to the actual spans of your project.
- Plan for accessories: end caps, connectors, base plates, etc.
- Think about transport: standard lengths range from 50 cm to 400 cm depending on the model.
- Consult an engineer for complex configurations.
FAQ
Q: What is the difference between distributed load and point load? A: Distributed load is applied uniformly over the length (kg/m). Point load is applied at a single point (kg). A load table gives both values.
Q: Can I use a WRF-29 for a 6 m span? A: Yes, but the load capacity is limited to 26 kg/m distributed and 10 kg point load. For heavier loads, prefer a WRS-40 or WRS-4060.
Q: Are the load values certified? A: The data provided comes from TÜV Rheinland tests. Each model has its own load table.
Q: Do you offer custom lengths? A: The 290 mm models are available in standard lengths from 50 cm to 400 cm. Contact us for any specific request.