A combination lock is a type of lock which uses a sequence of numbers or symbols to open the lock. The sequence can be entered by a single dial which interacts with several discs; by using a set of rotating discs with inscribed numerals which directly interact with the locking mechanism; or through an electronic keypad. Types can vary from inexpensive three-digit luggage locks to high-security safes. Of course, unlike regular padlocks, combination locks do not use keys.
Following are the various types of combination locks out there:
1. Multiple dial locks
One of the simplest and most common types of combination lock, often seen in low-security bicycle and safe locks and in briefcases, uses 2 or 3 rotating discs or dials with cuts in them. The lock is secured by a pin with several teeth on it which hook into the rotating discs. When the cuts in the discs are on par with the teeth on the pin, then viola! The lock opens up.
This type of lock is commonly considered as one of the least secure types of combination lock; many of these locks can be easily opened even if you don’t know the correct combination. Opening the lock in this way depends on some irregularities in the mechanism. Unless the lock is machined properly, pulling the pin outwards causes one of the teeth to also pull, yet more strongly than the others on its corresponding dial. This disc is then rotated until a slight click is heard. This indicates that the tooth has settled into the cut of the dial. The procedure is repeated for the remaining ones, which results in an open lock (and the correct combination) in very little time.
2. Single dial locks
Some combination locks found on lockers or safes may use a single dial which deals with several parallel discs. This type of lock is opened by rotating the dial clockwise to the first symbol or number, counterclockwise to the second, and so on in an alternating fashion until the last code is reached. The dials basically have an indentation, and when the correct combination is entered, these align, allowing the latch to fit into them and open the lock.
Differences between a Key Padlock and a Combination Padlock
Choosing a secure padlock can be a hectic task, so why choose one instead of the other? While there is, of course, a major difference in how users interact with a key padlock as opposed to a combination padlock, all locks basically work the same. A key padlock uses the key to align the tiny pins inside the lock while a combination padlock, on the contrary, lines up with the teeth on the pins inside the lock. In the case of a single-dial lock, the pins line up, releasing the shackle when the correct combination is entered.
So, which is more secure? Experts believe that a key padlock is actually more secure than a combination lock, because a combination lock with a three number code can be typically cracked in about 40 minutes, while a code with four numbers generally takes from four to five hours to crack. While that might seem like somewhat of a longer period of time, thieves who have a whole night to break into your home or your safe may not think it is much of a challenge.
While a key padlock can be picked, they are considered more secure than their combination counterparts. Insurance companies rarely, if ever, cover property or possessions protected by combination padlocks. A key padlock becomes even more secure if the shackle can be further protected from saw or bolt cutters by being enclosed.
Padlocks provide businesses or individual users a way to protect areas or possessions when they are left unattended. This can include tools at a business or job site, lockers at work or school, and any area that needs to be locked up to prohibit others from entering. This is not only a safety issue, as trespassers can become injured or worse when entering an area such as a construction zone, but it is also an insurance issue. Insurance companies require businesses to use locks to protect their equipment or close off certain areas to prevent injury. This usually means that not just any lock can be used but only those approved by the insurance company. This is determined by a joint effort between the insurance company and the padlock manufacturers to determine which types of locks are best for security.