What is a number wheel?

A number wheel, also known as a Combination Lock or Master Lock, is a type of locking device commonly used to secure items such as wall safes and padlocks. The wheel combination of a number wheel typically consists of 3 or 4 numbers that must be spun in the correct order to unlock the device.

Number wheels are often used to protect items that would normally be difficult to store safely, such as jewellery, cash and sensitive documents. A common type of number wheel combination lock is found on padlocks and is usually numbered 0-39 or 0-99. The numbers must be lined up in the correct order for the device to unlock; this cannot be guessed since the combination is unique for each lock.

For example, when using a 4-number combination lock (like those found on bank safe deposit boxes), you would need to spin all four wheels in the correct numerical order. Number wheels can also have letters printed on them instead of numbers which adds an additional layer of security since there are more possible combinations from which to choose.

When turning each wheel, some notches will more easily catch than others; this is known as 'hanging'. When turning each notch, it is important that you do not hang any of them since this could modify your desired result significantly and make your unlocking attempt unsuccessful.

Number wheels offer an additional level of security for their users and are far more reliable than traditional keypad-based devices because there are no keypads which can be easily broken into by an intruder. Furthermore, buyers should always buy their devices from reputable dealers since counterfeits may lack quality control which could affect how easily they unlock in the future.