Spigot Truss vs Bolt Truss for Events: A Buyer’s Comparison
When planning an event, choosing the right truss system is critical for safety, efficiency, and budget. Two common types are spigot truss (also called pin or cone truss) and bolt truss. This article compares their features, load capacities, and ideal use cases to help you make an informed decision.
What Is Spigot Truss?
Spigot truss uses a male-female connection: one end has a protruding spigot that slides into the next section’s socket, and a locking pin secures the joint. This design allows for rapid assembly without tools. Spigot truss is widely used in events where speed is essential, such as concerts, trade shows, and exhibitions.
What Is Bolt Truss?
Bolt truss connects sections using bolted plates or flanges. Each joint requires multiple bolts, making assembly slower but often providing a more rigid connection. Bolt truss is common in permanent installations or heavy-load applications.
Key Differences
Assembly Speed
- Spigot truss: Tool-free, quick connect/disconnect. A crew can assemble a large structure in minutes.
- Bolt truss: Requires wrenches and more labor; assembly time is significantly longer.
Load Capacity
- Spigot truss systems from reputable manufacturers like WRF-29 Ladder Truss offer proven load ratings. For example, the WRF-29 at 2m span supports 340 kg/m distributed load and 340 kg point load.
- Bolt truss can achieve higher load capacities due to the bolted joints, but modern spigot truss designs (e.g., WRS-4060 Square Truss) handle substantial loads: at 4m span, 805 kg/m distributed and 1610 kg point load.
Structural Rigidity
- Spigot connections have a small amount of play, which can be negligible in most event setups.
- Bolt connections are stiffer, preferred for long spans or heavy point loads.
Cost
- Spigot truss typically costs less in labor due to faster assembly.
- Bolt truss may have lower material cost but higher labor expense.
When to Choose Spigot Truss
- Temporary events: Concerts, festivals, corporate events where fast setup and teardown are crucial.
- Modular structures: Grids, towers, and arches that need frequent reconfiguration.
- Light to medium loads: Most lighting, sound, and LED screen rigging.
Example: A 6m span using WRS-29 Square Truss supports 317 kg/m distributed load, sufficient for many event applications.
When to Choose Bolt Truss
- Permanent installations: Theaters, studios, stadiums where structure remains in place.
- Heavy loads: Large video walls, heavy lighting rigs, or suspended equipment.
- Long spans: Over 12m where maximum rigidity is needed.
Load Capacity Comparison (Spigot Truss Examples)
| Model | Span (m) | Distributed Load (kg/m) | Point Load (kg) |
|---|---|---|---|
| WRT-29 Triangle Truss | 6 | 109 | 327 |
| WRS-30 Square Truss | 4 | 488 | 1466 |
| WRS-4060 Square Truss | 8 | 247 | 988 |
| WRS-52 520x520 Square Truss | 10 | 241 | 923 |
These figures are TÜV-tested and represent safe working loads.
Sourcing Tips
- Always verify load certificates. Reputable suppliers provide TÜV or equivalent testing reports.
- Check material: 6082/6061-T6 aluminum is standard for high-strength truss.
- Consider truss dimensions and chord sizes (e.g., 50x3mm main tube) for compatibility with existing inventory.
- For spigot truss, ensure the locking pin mechanism is robust and easy to operate.
FAQ
Q: Can spigot truss be used for heavy-duty rigging?
A: Yes, many spigot truss models like WRS-4060 and WRS-52 are designed for heavy loads. Always check the load table for your specific span.
Q: Is bolt truss safer than spigot truss?
A: Both are safe when properly engineered and used within rated limits. Spigot truss has a proven track record in events worldwide.
Q: How do I choose between spigot and bolt truss?
A: Prioritize spigot for speed and modularity; choose bolt for permanent installations or extreme loads.
Q: What is the maximum span for spigot truss?
A: Spigot truss can span over 12m with appropriate models. For example, WRS-5060 supports spans up to 9m as per its load table.
Conclusion
Both spigot truss and bolt truss have their place. For most event professionals, spigot truss offers the best balance of speed, cost, and performance. Evaluate your specific load requirements, assembly frequency, and budget to make the right choice.