How Padlocks Work

Learn about the standard iron padlock to understand the main parts, how they work

and also how to bypass the mechanical security features to pick the lock.

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Padlocks come in many shapes colours and sizes. They have been around for hundreds of years, ranging in complexity of design by different people and

civilisations depending on the technology and manufacturing processes they had available. With the industrial revolution came the mass-produced padlock which

eventually settled on a pin tumbler design. Called so because inside are some pins and a barrel which rotates or tumbles over.

These are strong mechanical locks which are easy to mass produce and we find them used for everything from keeping our bikes where we left them to

symbolising the everlasting love between two people on a bridge, and then throwing the key away to ensure it can’t be undone. But these types of locks,

especially the cheap ones, can be unlocked without a key if you know the correct method and once we understand how the lock works we’ll learn how to pick

the lock.

When we look at a padlock the most noticeable feature is the U-shaped shackle at the top. In the unlocked position, one end of the shackle pops out of

the main body allowing this component to rotate freely. On the inside surface of the shackle we will find two notches. These form part of the lock mechanism

and we’ll see that part shortly.