Adding a lock to a desk drawer is a good idea if you wish to store personal items, financial documents or other types of private materials in the desk. Be selective about what you choose to store in a locked desk drawer. The simplest lock to buy and install is a surface lock. Follow a few steps carefully, and you will have a lockable desk drawer.
Examine the desk drawer. Check to make sure the drawer face itself is thick enough and strong enough to mount the surface lock directly onto its surface. Measure the thickness of the drawer face. Make sure you have at least 1/2-inch thickness where you want to mount the lock.
Look closely at the top frame the drawer closes against. Measure and make sure the piece that meets the drawer when it is closed is at least 1/2-inch thick--the thicker the better. Make sure the piece that will hold the locking bolt receptacle has enough thickness to create a strong, secure locking hold.
Locate the lock on the face of the drawer. Find the centre point of the drawer. Measure the entire width of the face of the drawer. Divide the total number of inches by 2, to find the centre point. For example, if the drawer face is 15 inches wide, the centre point is 7 1/2 inches. Plan to centre the lock at the centre point.
Hold the lock in place, where you wish to install it, against the face of the drawer. Use a pencil to draw in the outline of the screw holes onto the front, top centre of the drawer front.
Mark the exact location of the matching bolt receptacle that will be installed into the drawer frame. Make sure these are drawn in and matched up exactly. Do not get these two pieces, the lock assembly and the bolt receptacle, misaligned. Get the alignment wrong, and the lock will never work properly.
Use a drill and a wood drill bit slightly smaller in diameter than the screws which will hold the lock in place. Carefully drill the two holes that will receive the mounting screws. Place the lock onto the drawer and attach the lock to the drawer with the screws.
Install a mortise lock if your wood working skills are sufficient to carve out the notch for the lock. A mortise lock will require you to cut out a wedge or pocket into the drawer and frame to set it in. Mortise locks are designed to be installed flush with the wood surfaces, whereas a surface lock simply screws into place on the wood surface.
Although desk drawer locks can offer a degree of security, they are not absolutely impenetrable.