Removing a broken key from a shop door.
This happens because the keyhole becomes clogged with accumulated dust and dirt over time, which prevents the key from rotating freely. To lower the chances of this happpening, regular lock maintenance should be carried out by spraying WD-40 into the keyhole, then inserting the key and rotating it to free the keyhole of dirt and dust.
For locks that are constantly exposed to the external environment, or exceptionally dusty and dirty areas, lock maintenance should be carried out twice a year. An example would be main door and gate locks that face the common corridor. For locks that are housed indoors, lock maintenance should be carried out at least once a year. An example of this would be the room doorknob.
In instances where the customer does not have a spare key, he can opt to change the lock.