security door locks | door security devices

One of the most important functions of an external security door locks is that it should keep out burglars. In fact, the most popular point of entry for housebreakers is through a window, but it is still good sense to make it as difficult as possible for them to walk through a door. One of the most common security door locks devices for external doors is a night latch. Most people would refer to it as a lock, but there is a difference: both locks and latches have a bolt, but a latch bolt is sprung so it closes automatically. To open the latch, you turn a handle inside or a key outside. A lock can be closed or opened only by a key. A lock or latch that is actually housed in a hole cut in the body of the door is known as a mortise lock or latch. If it is fitted on the surface of the door, it is called a rim lock, or latch. A night latch is a rim latch. It is fixed to the back of the door, and the keep into which its bolt locates is fitted to the back of the frame.

Security Door Lock This latch is the easiest of all security devices to force. Although it has a catch to prevent the bolt from moving, the only value of this is to stop the latch from closing and locking you out if, for instance, you go outside for a moment without your keys. It is useful to have a latch on an external door. When you are at home, it keeps the door closed without your having to lock it, but when you go out you need greater security. Some security door locks like night latches can be deadlocked both from inside and out. These are more secure than the simple latch, but they are no substitute for a mortise lock on external doors. When you are out the only protection for the door by which you have left is the lock you close with a key as you go, so make sure it is a good one. Buy a good quality mortise lock, with five levers and steel roll bars inside the bolt, so that it cannot be sawn through. If your home has two external doors, the back door can have bolts instead of, or in addition to, a mortise lock. If you fit it with both, it will be more secure than the front door. This can be an advantage because usually the back of a house is more vulnerable, as a burglar at work will be less visible there than at the front. Cheap barrel bolts that have the staple (the part into which the bolt locates) fitted to the inside face of the frame are not very secure, for a door held by these can be pushed in. It is much safer to fit bolts with staples in a hole bored into the side of the frame.

Better still, fit mortise bolts, which are like simplified mortise locks. It is not just at the lock edge that a door needs protection. It is just as vulnerable to a determined thief along the hinge edge. If the hinges are weak or not securely screwed in place, they can easily be broken off, if forced. So replace any security door locks that are in doubtful condition, and insert longer screws instead of the existing ones. Another way to strengthen the hinge side of the door is to fit bolts there, making it less easy to force the hinges. These are variously known as hinge, stud, or dog bolts. They are fixed to the frame, and locate in holes bored in the door when it is closed. You can also fit a spy hole as a means of checking on the identity of callers before you open the door. Alternatively, you can light a door chain. Another worthwhile door security device is some strong, wide metal trim around the letter plate, to prevent a determined thief from trying to saw the door in half.