Beyond part 1’s discussion on rekeying, it is helpful to further explain some of the concepts. Knowing more of the bigger picture can help when learning to rekey locks. Many can forget the overall goal and make mistakes one would not normally make when being distracted by small details. By remembering the goal of rekeying locks, to fit a key to an existing lock cylinder, a new technician may be less frustrated if small details are not remembered at first.
LOCK CORE REMOVAL
Once the lock cylinder is successfully removed from the knob, lever, or similar housing, a technician can continue in the process of the rekey. If the lock has an existing key, it is good to first remove the plug clip (if present) on the back of the lock. Some cylinders may also us a screw on plug retainer with a spring loaded detent. Insert the existing key and turn the housing 45 degrees in either direction. Be sure to rotate the housing and not the plug/key itself. The key should not have turned, rather the cylinder around the key. This will keep the bottom pins from spilling and is good practice in times where creating an existing key is necessary. Push the plug out of the cylinder using a follower. In times where there are no existing keys, it will be necessary to pick or shim the lock to remove the internal plug.
REKEYING THE LOCK CORE
Upon successful removal of the plug, remove the existing key and pins. Insert the new key with corresponding bottom pins. If there is uncertainty regarding the depths of the key and the needed bottom pins, a technician can use a depth tool, insert and read the key on a code machine, or compare the key against a space and depth key set. The pins should all sit very flush with the lock plug when the key is inserted.
LOCK PLUG REINSTALLATION STEPS
Using a reversed method to removal, push out the follower with the plug. It is often a helpful test to push the plug through with the key inserted. If there is any resistance, it is a sign of a pin being too tall. This pin should be traded out for a shorter bottom pin. A crucial step many newcomers forget is the C or E clip/screw on retainer reinstallation. Without it, all of the pins/springs will come launching out when the key is removed causing much more work than the rekey itself.
Put the lock cylinder back in the knob/lever housing along with necessary parts and the job is done!