A Rim Lock : Not Good For Security.

What Is A Rim Lock?

Fitting A Rim Lock Will Not Enhance The Security Of Your Home.

This type of lock has been around for many years. It is rectangular in shape and fitted to the surface of the door, usually on the inside, and is not set into the door.

Likewise, the keeper (cup or box) is mounted on the surface of the frame.

Usually the lock is secured to the door by just four screws and the keeper by two screws.

As you can imagine, it would not take too many kicks, or shoulder barges, to the outside of the door to burst it open.

All the burglar has to do is employ enough brute force to wrench out the two screws of the keeper and the door is open; he is in your home.

A rim lock may function well as a simple privacy lock on an internal door, but is in no way robust enough to serve as a security lock and is not recommended as the sole lock for external doors.

Two types of rim lock are manufactured.

There is the night latch type that has an angled end to the bolt.

These commonly have a thumb turn that is used to exit from the door; the door clicks shut and locks without the use of the key. You need to use the key when entering. 

These latch locks are vulnerable to being slipped open by thieves using a credit card or similar piece of plastic.

Slightly more secure is the deadbolt type of rim door lock.  The dead bolt has a flat end to it and, unlike the night latch, will only lock with the use of the key. This means that it cannot be carded open.

However a rim deadbolt lock is still mounted to the  surface of the door and leaves the door unable to stand up to a kicking attack.

brass rim lock

Polished Brass Vertical Rim Lock Set.

If They Are No Good At Protecting My Home, Why Is There One Of These Locks On One Of My External Doors?

Today it is rare to find one of these locks fitted to a front door, but they are sometimes still found on exterior doors such as one leading out from the kitchen. 

If the door is very old the lock may have been fitted simply because there was very little else available at the time.

Perhaps the door is not of suitable construction to take any other type of lock. It may be too thin to allow for A Lock to be Mortised into its edge, the door-frame may also be too thin to set a strike plate and cup into it.

If that thin door is an exterior one then you really do need to get it changed. Interior quality doors should not be fitted externally; they can be busted open too easily. If the frame is thin, get that changed too.

It could be that the lock has been retained simply because it looks good and fits in with the style of decor of the home.

Some folks find the large rectangular shape aesthetically pleasing, particularly in polished brass or matt black iron. There is quite a trade in refurbished and reproduction antique locks.

Another possible reason a rim fitting lock was chosen might just be because these locks are comparatively easy to fit –but considering the loss of security that is a pretty poor reason.

I Want To Keep My Decorative Rim Lock.

If for some reason you wish to retain a rim box lock on an external door you will need to supplement it with additional locking, that is a must do, otherwise the door will in no way be secure.

The traditional method of increasing security was by fitting bolts to the top and bottom of the door, but of course you cannot use the bolts if you exit from that door.

Also bolts would not be suitable for a door with glass panels; a burglar could simply break the glass reach in and unbolt the door.

Additional security means another lock, one that is not merely attached to the surface of the door.

To sum it up, a rim lock is good for internal doors, cabinet or closet doors or draws, but not as the only means of locking an external door.


Rim Lock.

Make High Security Door Locks Part Of Your Home Security Plan.