Harrow Glass Help with -Security:

  • Night Latches

Night Latches are used in conjunction with the locking rim cylinder. The rim cylinder is operated from the front of the door and turns the night latch which is fitted to the inside of the door. They are usually used on front doors in conjunction with mortice sashlocks or dead locks. Most night latches are available with a 40mm ( Narrow ) and 60mm ( Standard ) and are available as a standard security lock and a BS 3621 : 2004 kite marked lock. 

BS 3621:2004 locks are Insurance Approved to comply with your home and business insurance regulations.

How to Measure the door for a Night-latch


Please note if replacing an existing night-latch the measurement 'B' is either 40mm or 60mm - this is the measurement from the edge of the door to the centre of the hole (where the rim cylinder goes in). Measurement 'B' is more commonly known as the backset.

You therefore can choose any of the following night latches if you are fitting a

Rim_diagram


A=Case width
B=Backset
C=Case Height
D=Case Depth
E=Handle Projection

nightlatch from 'fresh'. If replacing the night latch ensure that you choose either a 40mm or 60mm backset nightlatch.



Video On How to fit  Nightlatch

 


Mortice Locks

A mortice lock is 'morticed' into the door.  If you are replacing a mortice lock, it is important that you know the size of the your existing lock to ensure that your new lock will fit into the same hole.  Mortice locks are available in sashlock or deadlock variants, so it is important that you know which one you require.

Measuring the backset

The measurement from the front plate of the lock to the back of the lock case.  A number of different backsets are available but the most common in the UK are 64mm (2.5") or 76mm (3").

Measuring the centres

If you are fitting a sashlock to enable the lock to be operated in conjunction with a door handle, you will need to measure from centre of the 'follower' - the hole where the handle spindle goes, to the centre of the keyhole.

Typically in the UK, the most common size is 57mm, although other sizes are available,

Sashlock or Deadlock?

A sashlock is typically used on back doors and has a latch and a bolt.  The latch is operated by a handle and the bolt is operated by key.

A deadlock is typically used on front doors in conjunction with a nightlatch and has a bolt only.  The bolt is operated by key.

How many levers?

A mortice lock is either operated by a euro cylinder or by integral levers,  The more levers a morice lock has, the more secure it is.  Look for a British Standard 5 lever mortice lock for all external timber doors.


How to Fit a Mortice Lock


                     
 
 
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