Some models of filing cabinets may not have locks, and you might wish to add one for security purposes. Fortunately, adding a lock to a filing cabinet is a quick and easy procedure. Be aware that no lock is impregnable, and truly important papers may need to be secured in bank vaults or fire-proof home safes. But for simple storage and security needs, adding a lock to a filing cabinet may suffice for less important document storage purposes.
Choose a location for the lock. A location higher on the filing cabinet door will hinder the top edge of the drawer from being pried open. With that in mind, choose a location about one inch below the top lip of the drawer.
Wet cotton balls with rubbing alcohol and clean the location chosen for the lock. Rubbing alcohol will effectively remove grime and dust, and won't leave behind a water-based residue that may interfere with the glue's adhesion. Clean the front of the drawer and side of the cabinet where you have chosen to place the lock.
Apply super glue to the back of the hasp and U-bolt. The hasp and U-bolt are in two sections. The U-bolt part will go on the front of the drawer, the hasp section will go on the side of the cabinet. Apply super glue to the backs of both pieces.
Affix hasp and U-bolt sections to the cabinet on the cleaned areas. Stretch masking tape across both to hold everything in place.
Remove tape carefully after glue has set to prevent marring paint.
Attach a small padlock to the U-bolt when glue has set and tape is removed. This will effectively secure the filing cabinet and help prevent unwanted access.
Repeat these steps for additional cabinet drawers as desired.