Combination locks are frequently used for securing lockers, gates, boxes and other small items against theft and unauthorised access. The most common type of combination lock is round with a turnable dial on the front. The dial is rotated one way, then the other, then back again so that the arrow or line on the case matches up with the numbers on the dial that make up the combination. If you have lost the combination to a lock of this type there is no reason to reach for a hacksaw and spend half an hour (and several blades) ruining your lock to get it open again; there is a simple and reliable solution to your problem.
Pull the body of the lock firmly away from what it is secured to and hold it there. There should be constant tension between the latch and the body of the lock. This tension will make it possible to hear and feel when the dial reaches the numbers in the combination and the mechanism engages.
Turn the dial to the right until you hear a clicking noise (this is the sound of the lock mechanism engaging). Turn the dial an additional two numbers, but no farther. Write down the number the dial is now on for future reference, as it is the first number in the lock's combination.
Turn the dial to the left until it stops. Do not turn it any farther. Write down this number, the second in the three-number combination. Be sure to continue pulling on the body of the lock.
Turn the dial to the right until, at the final number in the combination, the lock should pull open. Note this number; you now have the entire combination for your lock.
If the lock is free and not attached to anything, you can create tension in between the latch and main body by inserting several fingers of your left hand (right hand if you are left-handed) into the space between the latch and casing of the lock and pushing the two apart. If this method doesn't work for your lock, or if you have one of the several other kinds of combination locks in common use, more destructive means may be necessary to open it. Using a hacksaw is slow and time-consuming, and you will likely go through several blades before you are through the hardened steel latch. A good tip is to use an electric reciprocating saw (with a metal-cutting blade) to cut through the latch.