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What is wrong with this filing cabinet lock mechanism, and what options do I have to improve it? - Home Improvement Stack Exchange
Wood Lateral File Cabinet Lock - #205 no key
Plans resource for lateral file cabinet?
Can I safely secure these two filing cabinets together on top of another with magnetic discs? (pictures included!)
Usually those locks have a nut behind - that is how they are held in place. If not then there is a type of spring clip - you need to look.
Then you need to get the plate fixed back into the correct position if you want the locking system to work. Or remove it and not worry about that locking system.
If you need to secure that cabinet shut then a rod straight down the front through a couple of added brackets will work with a padlock.
Just be aware that a cabinet like that can be opened like a can if they really want the stuff.
The bracket had been bent backwards (screwdriver and hammer) to force it of the end of the lockbar on back of lock.
That lockbar normally fits inside the "L" cutout on the bracket which just hangs there. Rotation of the key would turn the bar to move the bracket up or down. A little elbow grease and pliers and it could be bent farther back to be parallel to the drawer if locking the cabinet is not a concern.
Or: remove the lock via the nut or spring clip as mentioned in the above answer. Take the same pliers and elbow grease and bend it back parallel to the front and lift it with one hand and insert new key assembly to hang bracket as describe above.
Replacement locks are easily obtained. Compare your old one to find exact match.