Attach the metal lock hasp to the storage box. Ensure that the round head portion of the bolt is on the outside of the box and the metal nuts are attached to the bolts inside the box to keep someone from unbolting the hasp to get inside the box.
Weld the chain to the outside of the storage box. Select a location for the storage box so that the chain can be attached or wrapped around a secure, permanent object such as an exposed wall stud, permanent metal fixture or heavy object.
Secure the chain with the storage box attached to an immovable object using one of the padlocks. Keep the keys for the storage box in a secure location that is easy to remember but away from curious hands.