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Lock and key

technology Maturity 11-13 Next article →

A lock is a device used to keep things safe.

Solex 99 30 padlock with keys (DSCF2659)
Solex 99 30 padlock with keys (DSCF2659)

It can be a mechanical tool or an electronic system. You might use a metal key, a plastic keycard, or even a fingerprint to open one. Some locks only open from one side, like a door chain. A key is the tool that operates the lock. Most keys are made of metal like brass, nickel silver, or steel. A key has two main parts called the bow and the blade.

Key anatomy
Key anatomy

The blade slides into the keyway, while the bow is the part you hold to turn it.

Many different ways exist to make a lock work. In a warded lock, metal obstructions called wards block the path.

Wardedlock
Wardedlock

A key must have the right notches to pass these wards. A pin tumbler lock uses a different method. It uses pins of different lengths to stop the lock from turning. When you slide the correct key in, the grooves on the blade lift the pins. These pins must line up perfectly at a line called the shear line. Once they align, the cylinder can rotate and the lock opens. Some modern electronic locks use an actuator to move the bolt.

People have used locks for over 6,000 years. One very old example was found in the ruins of Nineveh.

Scorpion Lock, Bronze from Nalanda, Bihar, dating from 10th century A.D.
Scorpion Lock, Bronze from Nalanda, Bihar, dating from 10th century A.D.

Ancient Egyptians used wooden pin locks. These used a bolt and a key to lift pins inside a fixture. The Romans later invented metal locks and used wards for security. Wealthy Romans often wore their keys on rings. This kept the keys close and showed they had valuable things to protect. In the 17th and 18th centuries, some locks were decorated with leaf shapes.

Dronkenmansslot
Dronkenmansslot

These were sometimes called "drunk man's locks" because they helped people find the keyhole in the dark.

Inventors have spent centuries making locks harder to pick. In 1778, Robert Barron invented the lever tumbler lock.

Chubb lock
Chubb lock

This lock uses levers to keep the bolt from moving. Later, Jeremiah Chubb improved this design in 1818. He created the Chubb detector lock to stop burglars. A lock-picker once tried to break his lock for three months but failed. In 1784, Joseph Bramah made a cylindrical key lock. He offered a £200 prize to anyone who could pick it. It took an American named Alfred Charles Hobbs 16 days to open it in 1851.

Mendel I 072 v
Mendel I 072 v

Most locks we see today come from these famous inventors. The modern pin tumbler lock was perfected by Linus Yale Jr. in 1861. He used a small, flat key with serrated edges. This design is very similar to the locks used on many doors today. We also use electronic locks that work with smart technology. Some locks connect to your smartphone using wireless signals. Others use a radio code from a smart car key. These new tools help us secure our homes and cars in a digital world.

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🖼️ Images & Media (12)
File:Solex 99 30 padlock with keys (DSCF2659).jpg
Solex 99 30 padlock with keys (DSCF2659).jpg
File:Scorpion Lock, Bronze from Nalanda, Bihar, dating from 10th century A.D..jpg
Scorpion Lock, Bronze from Nalanda,...
File:Lock MET cdi55-61-5.jpg
Lock MET cdi55-61-5.jpg
File:Dronkenmansslot.jpg
Dronkenmansslot.jpg
File:Tibetan Lock and key - Dhankhar Gompa, Spiti. 2004.jpg
Tibetan Lock and key - Dhankhar Gompa,...
File:Chinese lock.JPG
Chinese lock.JPG
File:Key anatomy.jpg
Key anatomy.jpg
File:Chubb lock.jpg
Chubb lock.jpg
File:Mendel I 072 v.jpg
Mendel I 072 v.jpg
Copia llave video.ogv
File:Wardedlock.jpg
Wardedlock.jpg
File:Palestine Nakba Day demo in Berlin.jpg
Palestine Nakba Day demo in Berlin.jpg
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