Night latch is the correct terminology for what most people call a Yale lock. It is simply a latch operated by a turn from one side and by a key from the other side. Sometimes they are called slam locks, due to the reason that once the door is closed behind you need a key to come back through the door.
The majority of households have a night latch on their front door and in the vast majority of cases it is a visible surface night latch. It is possible however to have the night latch function concealed in the door as a mortice night latch. This type of attachment is common found on communal flat entrance doors.
Roller Bolt Systems
There is also a version of the surface night latch which is known as Roller Bolt Night Latch. As the name suggests the latch incorporates a roller and the door when closed just remains latched on the roller. It is not locked until either the internal knob is rotated or the key is turned from the outside. It is very commonly found on individual flat front doors, within a block of flats, since these doors need to have closers in order to meet fire regulations. In this situation it was not uncommon for occupants to find themselves locked outside without a key, when a standard night latch was used.
We strongly advise that all front doors are fitted with a night latch and an adequate five lever insurance rated lock for ease of use and security. For added peace of mind, several night latches now meet the British Standard 3621, for insurance rated locks.
