We used the Stanley mobile tool box as a work site locker. There was plenty of room inside for us to stow our portable router table along with a circular saw, drill/driver, battery charger ...

You can then purchase additional units to stack on top of the base box and create a multi-level, portable tool storage system that allows you to transport your gadgets securely between job sites.

holes from the bottom box through the top chest, staying away from any locking mechanisms. Secure them together with 1/4-in.