Locking Mechanisms for your Home
The earliest locking mechanisms found by archaeologists date all the way back from ancient Assyria. Unlike modern locks these were simple and relatively bulky. When the industrial revolution came around in the 18th century the complexity of locks increased as the supplies to make them and the reasons to keep items secure increased as well.
During the Industrial Revolution the Pin Tumbler lock was invented using a series of small springs and cylinders to prevent the lock from working without the correct key. This type of lock was much smaller than previous locks and is still used today. This is what you now see on many doors both commercial and residential.
When choosing locks for your home choose the best one for your purposes. Interior doors may not need a lock, and while many homes come with them installed the type used is usually ineffective enough that an intruder can easily bypass them with a bit of brute force. Your entrance doors on homes most likely have a deadbolt and a knob lock. While this set up is decent enough many homes also tend to have windows right next to the entrance door allowing thieves to break the window to turn the knobs.
Here are a list of various types of door locks and the purposes behind them. Please note this is not exhaustive of all lock types.
Padlocks are portable locks not usually used for homes but for sheds, fences, shop shutters, lockers and luggage backs. Some use keys while others use combinations. They are relatively easy to break and can be cut with a saw if not case hardened. You are probably not going to use these for your home but for garden sheds. Remember to take a good brand, cheaply produced locks can be broken into by removing the locking mechanism with a screwdriver.
These common locks are the ones you most likely already have on all of your bedroom doors and front door. One side is usually a keyhole while the other is a knob. While easy to use it is relatively weak against brute force. A hammer is all it takes for someone to smash off the knob and then remove the lock. In addition the actual mechanism is usually vulnerable to being picked. The main use of these locks is to provide privacy in your home.
Lever Handle Lock:
The lever handle lock is basically the commercial equivalent to the Knob Lock. They are easy to open for handicapped people and are common in office buildings and sometimes apartments. Depending on the model the lock can be forced by with a torque attack thanks to the long handle.
Usually found on entrance doors the deadbolt’s main weakness is that the inside side usually has an easily turned knob to disengage the lock. Most doors have small windows (Sidelites) that allow you to take a look at guests outside but can be easily smashed to allow an intruder to turn the deadbolt. You can remedy this by installing a deadbolt that uses a key on both sides. However this can be a major hazard in the event of a fire where someone will need to get a key to unlock the door. Therefore you should leave the key near the door, possibly on a wall or a in a box. Alternatively metal bars or reinforced glass can be used to prevent access to the knob from the outside.
Mortise locks can be found on your storm doors, commercial doors and apartments. They are harder to install but more durable than other locks. They work as both a door knob and a dead bolt.
Euro Profile Cylinders:
These locks can be considered a smaller version of a deadbolt they are found mainly in sliding doors in the United States but in Europe and Asia they are used in homes. Like a deadbolt they come in both single side lock with thumb turn knob and double side lock varieties. Unlike deadbolts they are much more fragile, because the connection between both halves of the lock is thin allowing someone with pliers to snap it it half.
Jimmy Proof Deadbolt:
The last lock on this list is the Jimmy Proof Deadbolt. These do not require as much modification to the door because they go on the surface. These are resistant to being forced from the outside and may have a toggle to prevent lockpicking. These are common in apartments and double doors.