Lock work

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Locks are an excellent invention, but the lock mechanism is rather simple. The way locks work can be summarized in one sentence: they use a key to open them. Most people assume that there is some high-tech magic going on when a key turns a doorknob and unlocks it because they have never taken the time to learn how locks work. This post will break down the basics of what goes into opening a lock so you’ll have a better understanding of why people would ever need keys in the first place!

What is a lock

In the very broadest sense of the word, a lock is a device that keeps valuables safe or restricts access to something that needs protecting. A lock can hold things out (protecting homes from intruders and banks from thieves) or keep them in (holding criminals in jail or animals in zoos).

Before the modern electronic age, locks were entirely mechanical and based on intricate mechanisms made from levers, wheels, gears, and cams. During the mid-20th century, locks became more sophisticated and automated and started to incorporate electrical and electronic mechanisms. But now information is valuable too and most of it is held inside hundreds of millions of computers that are all linked together through the Internet. Modern locks that protect computers are based on encryption – a way of securing information using complex mathematical processes.

How do locks work

Most mechanical locks are fitted to things like doors and cupboards and have two physically separate parts. One part is fitted to the frame (the static part of the door) and is essentially a sturdy, metal reinforcement for a hole cut into the door itself (to prevent the locked door from being opened with brute force). The other part of the lock fits into a rectangular hole in the door (known as a mortise) and consists of a metal mechanism that moves a heavy bolt into or out from the reinforced hole. The bolt slides from side to side when you turn a key clockwise or anticlockwise, so it has to be operated by a mechanism that can convert rotary motion (the turning key) into reciprocating motion (the sliding bolt) – something like a cam or crank. If that were all that a lock consisted of, every key would be able to open every lock. So the other essential part of a lock’s mechanism is a set of fixed or moving metal pieces (wards or tumblers) that engage with slots cut into the key, ensuring only one key can rotate, turn the cam, slide the bolt, and open the door.

Types of locks

Tumbler locks can trace their origins back to ancient Egypt, but the kind we use today is a more recent (19th-century), more sophisticated, and much more secure design – best known to most of us in the form of the cylindrical pin tumbler or Yale lock (developed by Linus Yale, Jr. in the 1860s).

Electronic locks do away with metal keys altogether; you’ve almost certainly used one if you’ve stayed in a hotel recently. Instead of a key, you have a plastic card (similar to a credit card) that has a magnetic strip on the back. When you slide the card into the lock, an electronic reader circuit decodes the information on the strip and checks for a match with a code stored inside it.

Biometric locks (featuring things like fingerprint readers or iris scanners) that grant access to a specific person rather than just any old person who happens to have the matching key. Sooner or later, sometime in the future, it’s likely that most locks will have some form of biometric security checking built-in.


Locks are an excellent invention and they come in all sorts of shapes and sizes depending on your needs. From mechanical locks that can trace their origins back to ancient Egypt or more recent electronic locks with biometric access security checks, there’s a lock for every situation from protecting homes from intruders to keeping criminals locked up tight behind bars.