anatomy of a road case

We asked Circle Three Designs owner Christopher Shalhoub about road cases and how to make informed decisions when ordering them. Here is his first article detailing the basic hardware used to make cases and the range of the quality and function of that hardware.

Circle Three Designs is a case company that has delivered it’s top quality, custom cases to some of the industries biggest Pop, Rock, Country and Hip Hop touring acts on the road today. They also have created cases in other diverse fields including medical and military contractors.

The following is designed to give a basic understanding of road cases and what to look for when ordering them. When getting a quote from a case company, make sure you know what you’re paying for.


Rivets hold road cases together so choosing the proper one is critical in designing and building a quality road case. there are two main choices, blind and split. Blind rivets create a stronger bond than split rivets but cost more and take longer to install.

Blind Rivet

The blind rivet is composed of the rivet and the mandrel. The mandrel is pulled through the rivet. The end expands and then the mandrel pops off. This is how the bond is created. blind rivets have the hole where the mandrel pops off.

Split Rivet

Split rivets are the fastest way to assemble mass production. They are easily identified by their solid heads. Split rivets have two tails that curl back to create the bond.


Rivets should always be backed by washers. If the rivet is up against a soft material like wood, it will eventually loosen and fall out.

Corner Extrusion

When the edge of the case is slammed into the wall, the aluminum along the edge is going to take the beating rather than the wood panel chipping or cracking. again, there are two main choices, single angle extrusion and double angle extrusion.

Single Angle Extrusion

Single angle extrusion is simply a piece of aluminum bent at a right angle. This sits over the edge of the case. The wood is riveted to the extrusion.

Double Angle Extrusion

Double angle extrusion has two channels where the wood slides into. Each piece of wood is supported by aluminum on the inside wall and outside wall. This provides more support for each panel.

Double angle extrusion makes for a significantly stronger case.

Double angle extrusion does weigh more so that is something to keep in mind.

It also costs more than single angle.

Edge Extrusion

There are three choices when it comes to edge extrusion (this is the section around the lip of the case that opens and closes): tongue & groove, hybrid, and slam shut. This part of the road case is important because it will keep the lid and base of the case in place. Think of a lift-off lid combo amp case and how important it is for the lid and base to securely attach.

Tongue & Groove Extrusion

This is the most common extrusion used. One is clearly the tongue and the other the groove and they mate together to form a secure fit.

Hybrid Extrusion

This is a similar concept to the tongue and groove. This extrusion is designed to be reversible. If you flip it around it will interlock with each other.

Slam Shut

This is where the lid and base of the case simply sit on top of each other. The edge might be capped off with aluminum U channel or simply left as bare wood. Many of the carpeted cases are designed like this.

 Tongue and groove creates the most secure fit.

The hybrid extrusion is usually used by smaller shops or DIY guys based on the fact that they can purchase fewer materials. The fit with the hybrid extrusion is simply not as secure as with the tongue and groove extrusion.

The slam shut is a cheap route that should be avoided under most circumstances.

Ball Corners vs Flat Corners

Ball corners are designed to take the initial impact of the case. When a case slams into the wall, the ball corner is going to take the hit rather than the wood panels or hardware.

Flat corners are used when there are size limitations and every 1/2” needs to be optimized. Flat corners are also used in certain designs where the case needs to open flush against itself. This is common in the table-top guitar tech cases.


Keep in mind that with flat corners, when the case is pushed up against the side of a trailer or up against another case, the actual case is going to take a lot of the impact. It is easier for hardware to get damaged or wood panels to break.

Hinges and Lid Stay

 Piano Hinge

The piano hinge across the back should be attached with steel rivets that are backed by steel washers. If the rivets are not backed by washers, they will eventually wear through the case and fall out. There is a lot of pressure and stress on this part of the case which is why the added strength of steel over aluminum is needed.

Nylon Webbing Lid Stay

Nylon webbing is commonly used as lid stays. For smaller cases, there may not be room to attached recessed steel lid stays.
The nylon webbing tends to get caught in the lid when closing and eventually frays.
Nylon webbing weighs less than steel lid stays so if every ounce counts, nylon is the best bet.

Recessed Steel Lid Stays

Recessed steel lid stays take the place of nylon webbing lid stays. They are stronger and last longer. They can handle the heavier lids without failing.

Surface Steel Lid Stays

Recessed hardware is almost always a better choice. There are certain designs where this is not possible and surface hardware is required.

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Help support Our Community by looking fresh

 Every sale of our “Flag” design merch donates $5 to touring based charities in hopes of doing our continued part in supporting the mental and physical health of our music touring community.

Help support Our Community by looking fresh

 every sale of our “Flag” design merch donates $5 to touring based charities in hopes of doing our continued part in supporting the mental and physical health of our music touring community.


Please Reach out with any questins or concerns you may have. 

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