A friend needed a tool box on his trailer and I chimed in and said we should tuck it in the frame rails.... Well, Many hours later it is complete but what a pain!
It's made out of 11ga. material so it can take some abuse. The bottom inside is lined with a thick rubber conveyor belt material that will hold up to tools and chains being thrown in. I added a locking T handle and a gas strut to hold the door up.
I used a little MIG, a little TIG and a plasma cutter to construct this box.
This was made in two pieces and then bolted together with sealant in between. I had to make it like this so I could slide the main box into the frame rails, if I didn't, the lid and top would have hit the bed before it slide into place.
This was the first tool box I've made so it was a learn as you go experience but in the end it turned out pretty decent.