If you’re building your own road case at home, choosing between single and double angle extrusions is one of the first decisions you’ll face. These aluminum profiles form the structural edges of your case, and each type affects how you design, cut, and assemble your panels. Whether you’re a seasoned builder or just starting out, understanding the differences will help you make smarter choices.
How Case Size Influences Structural Strength
Before diving into extrusion types, it’s important to note that the strength of a finished case depends primarily on its size. A small case under one meter long, carrying less than 50 kilograms, won’t benefit significantly from double angle extrusions alone. Larger cases, especially those over 1.2 meters or built for heavier loads, require more structural reinforcement—whether through extrusion choice or additional support like castors.
Panel Sizing and Calculation Differences
One of the most practical differences between single and double angle extrusions is how they affect panel sizing. With single angle extrusions, the plywood panels are cut to match the internal dimensions of the case. The extrusion sits outside the panel, so it doesn’t interfere with sizing calculations.
Double angle extrusions require more precision. Since the panels slot into the extrusion channels, you’ll need to subtract the channel depth from your panel dimensions. This adds a layer of complexity to your build, especially if you’re working with tight tolerances or custom layouts.
Assembly Methods and Workflow
Single angle extrusions require a road case’s base and lid to be first put together using a nail gun. Once the structure is complete, the extrusions are riveted on. This method is straightforward and works well for one-off builds or small batches.
Road cases built of double angle extrusions follow a different process. Panels are inserted directly into the extrusion slots, and the entire frame is riveted together in one go. This can speed up assembly and reduce the need for additional fasteners. For builders working on multiple cases or production runs, the time savings can be substantial.
Cost Comparison Between Extrusion Types
If you’re building on a budget, single angle extrusions are the more affordable option. They use less material, require simpler cuts, and don’t demand as much tooling. For hobbyists or small-scale builders, this can make a big difference in overall project cost as well as complexity in planning.
Double angle extrusions offer more strength and faster assembly, but they come at a higher price—both in terms of material and labor. It also involves more calculations to get the plywood panels that forms each face of the case accurate because the extrusion itself should be included in the overall internal dimensions of the finished product. This means you must obtain a side profile drawing of the double angle aluminum extrusion from the reseller or manufacturer in order to work out the panel dimensions. You work it out backwards starting from the desired case internal dimensions, minus the distance taken by the double angle extrusions. If you’re building cases for frequent transport or heavy gear, the investment may be worth it. Otherwise, single angle extrusions may be the more practical choice.
Real-World Strength and Load Considerations
While double angle extrusions are stronger in theory, real-world performance depends on more than just the extrusion profile. For example, a 1.2-meter case built with single angle extrusions and six castors—including two in the center—can outperform a double angle case with only four castors. The reduced span and distributed load make a significant difference.
So when evaluating strength, consider the full picture: case size, load weight, castor placement, and internal bracing. Extrusions are just one part of the equation.
Final Thoughts
Choosing between single and double angle extrusions comes down to your case size, load requirements, and build preferences. Single angle extrusions offer simplicity and lower cost, while double angle extrusions provide faster assembly and potentially greater strength. For most DIY builders, understanding these trade-offs is key to building a case that performs reliably without overcomplicating the process.
If you’re ready to start your next build, explore our full range of road case aluminium extrusion options and get the materials that match your specs. At Armor Road Cases, we supply both single and double angle extrusions for 7mm, 9.5mm, and 12.5mm panels—all in durable 2.0MM thicknesses.