Some time back I found a discarded leather belt with a broken buckle. I collected it, since leather should not be wasted, but didn't know what to do with it. Finally, I made it into an airport-security-friendly no-metal belt by designing a plastic buckle and using plastic rivets to hold the belt together.

I have to confess that I haven't checked how TSA feels about wearing this belt through security. The trip I was going to use it on got canceled due to weather.

Supplies

3D printer
filament
soldering iron or other heat source

Step 1: Print

Download my print files. I printed in ABS, but PLA should also work. The OpenSCAD file can be easily customized so you can adjust to match your belt dimensions.

Notes:

The buckle and tongue don't need any supports. Just print them flat.
The rivets will look a lot better if you print them with the shafts pointing up, but the shafts will be weak. I ended up rotating 90 degrees so the shafts were horizontal, and using a raft and supports. I cleaned up the print by chucking the rivet into a drill and running it against a file. The result still looked ugly, but it doesn't matter much because the belt covers the rivets when the belt is worn.

Step 2: Remove All Metal

Remove all metal from the belt. I used a cut-off wheel on a rotary tool to slice through the rivets on one side, and then forced them out with needlenose plyers.

In the last moment, I noticed that the belt loop was held together with a staple. I removed the staple and sewed it together instead.

Step 3: Assemble

Snap the tongue onto the buckle. You'll find it can easily come off. On the belt I have, it doesn't matter at all, because the leather part of the belt holds the tongue securely in place. If it does matter to you, soften the tongue near its bend with a heat source (heat gun, lighter or soldering iron), and then after insertion bend it securely in place with your fingers or plyers.

Step 4: Attach to Belt

Put the buckle onto the belt.

Insert plastic rivets through the old rivet holes. The shaft of the rivet should stick out of the ring. Melt the shaft down flat with a soldering iron or other heat source, pressing it flat. File if desired.