Combination locks can be a very effective way of providing quick, easy, and safe access to secure areas. You can get a combination lock in a number of different styles and types, and most of them are very effective for at least one application. There are, however, a few things that need to be taken into account to ensure your security is not compromised when using combination locks, which will be discussed below.
The simplest combination locks are combination padlocks. These consist either of a normal padlock casing with three to five wheels on the bottom, each with numbers 1-9 engraved in them. When you dial each of the wheels to the correct number the lock snaps open. This type of lock is called a "sesamee" lock after the most popular brand in this style, Sesamee. Another type of combination lock is the Master lock. These locks feature a dial on the front face with numbers 1-40 printed around the edge. To open the lock you spin the dial twice in one direction to the first number, once in the opposite direction to the next number and then directly in the opposite direction again to the third number.
While the quality of the machining does make a difference these are generally easily picked. If you know the trick a Master lock combination can be easily determined just by listening while manipulating the dial. Sesamee locks are somewhat more resistant; however, if there is sufficient space in between each of the wheels and the casing, with a combination lock pick it is possible to feel the correct combination while manipulating the wheels. The better the machining with these locks and the tighter the fit, the more resistant they are.
In addition to what has already been mentioned, the other types of combination lock do vary greatly, however, they all follow the same basic principle. Rather than a system of wheels or a dial, which are both susceptible to picking, you can get mechanical push-button combination locks. If you you're looking to pick, combination lock breaking is a lot harder on this type of lock. All locks can be defeated, however, so some research should be done before making a purchase decision. Some are better than others and some are so bad that they should be avoided altogether.
The main problem in this area is that combination door locks usually ship with a default combination preset into them. This in itself represents a potential security threat from employees of the manufacturer, retailer, and anyone else involved in getting the lock to you. Some companies use only a very small set of default combinations and these have become available on the web. So it is very important when buying such a combination lock to make sure that the lock combination can be changed.
Combination padlocks start as low as US$15 and mechanical combination door locks can go higher than $350. There is a great deal of variation in the quality in this wide range so it is a good idea to do a web search for reviews and picking information on the model name that you decide you want to buy before actually purchasing it.
