Knowledge Base

How Does a Padlock Work | Everything you need to know 2023

Sometimes you might wonder what’s inside the padlock and how it works. Well, padlocks are the most common device to protect our valuables in a public place, when we are not at home, and even for more purposes. This small and intricate system is used to connect two things such as a door and its jamb. They have a unique locking mechanism that uses a key.

   Learn more about padlocks, their main components, and the locking mechanism. Also, how padlock works and who invented them. Thus keep reading for more information!

About Padlocks

   Padlocks vary in size, color, and shape. These are very ancient inventions with a wide range of designs with the same operations according to the manufacturing method and technology. The first padlock has a pin tumbler design because there were only pins and a barrel that turns over when the key is inserted.

   Most padlocks have strong metal bodies excluding combination and disc padlocks. So, the body is a stronger part of the padlock; if it increases, the key inserting area and locking mechanism will also be larger.

   These are one of the strongest mechanical locks that can secure everything from bike to home. These locks can also be picked if the person knows the method. By using lock-picking sets, padlocks can be picked easily. So, depending on the brands, these padlocks can be cheap and robust.

Anatomy of Padlocks

   A padlock has three important components: body, shackle, and locking mechanism. However, its style can be different according to the model and manufacturer.

   The most crucial is the shackle that protects your valuables with a chain or latch. The shackle is a cut piece of strong wire or metal. It can be square, round, and even a toughened cable (mostly used with bikes, bicycles, etc.). The shackle is attached by the locking mechanism that is inside the padlock. This locking mechanism allows the shackle to move freely from the latch to access your valuables.  

   The body is the part that covers the padlock. The padlock body is also changeable, just like the locking mechanism and shackle. So, each manufacturer and padlock model has its own style. However, all padlocks are different, but they work on the same principles.

How does the Padlock work?

How does the Padlock work

   The most visible feature of the padlock is its shackle which is U-shaped. If the padlock is unlocked, one end of the shackle will come out of the body and can be turned freely. The shackle has two notches on the inside, and one part is shorter than the other. To lock the padlock, we push the shackle in the hole of the lock body.

   Then you’ll feel a click, meaning the shackle is occupied by the locking mechanism. The shackle is immovable and can’t come out of the lock body. To unlock the padlock, we have to insert the original key in the lock body’s keyway located at the bottom. After that, turn the key to release the shackle from the lock body. So, inside the padlock, the locking mechanism locks and unlocks the padlock. Let’s take a look at the main operations.

  • The first part of the padlock is a plug. When we insert the key into the padlock, it enters the plug by tracking the grooves for a smooth move.
  • When the key is rotated, the plug will be turned. There are various holes in the top of the plug. Each hole has a tiny metal cylinder that is called a key pin. Each pin varies in height and simulates according to the key profile.
  • There are chambers in the lock body which position the holes in the plug. Each chamber has a spring that forces another pin, called a driver pin.  
  • The spring forces the driver pin into the paralleling plug hole until it joins the key pin. In this case, the driver pin will be in touch with the key pin even if the padlock is turned opposite.
  • The joining between the lock body and plug is called the shear line. The driver pins will not touch the housing chamber and plug if the key is not placed in the lock. That means the plug can’t turn.
  • When the key is placed into the padlock, the key pin will go up and down according to the key shape until it is fully inserted. Once the correct key is fully inserted, the key pins will line up according to the shear line. The driver pins will align up and touch the housing completely, while the key pins will touch the plug. That means the plug can be turned easily now. Moreover, in case of the wrong key, the pins will not position, and the plug will not be turned too.
  • Having acquired the appropriate key and successfully rotated the plug, our next objective is to devise a mechanism to release the shackle while maintaining its secure retention, preventing unauthorized removal without the key.
  • At the conclusion of the plug’s structure, there is a metal lump known as a cam. This extension serves as a lever, utilizing its specially designed contour to exert force.
  • The lock is equipped with two latches on either side of the cam. These latches feature angled outer edges that securely fit into the corresponding notches on the shackle. A spring inside the lock provides tension, pressing the latches outwards and ensuring that the angled edges remain engaged with the notches. As a result, the shackle cannot be removed from the lock.
  • Each latch features a small arm at its inner end that extends and rests against the flat surface of the cam. One latch is positioned against the top edge, while the other is against the bottom. When the cam rotates, its shape causes the arms of the latches to be drawn inward against the tension of the spring, thereby releasing them from the notches on the shackle.
  • A spring is positioned beneath the longest end of the shackle within the primary body of the lock to simplify usage. This spring provides upward pressure, making it easier to remove the shackle. Additionally, the presence or absence of the shackle can be quickly determined simply by visual inspection, as the spring will cause the shackle to protrude when the lock is unlocked.

Types of Padlocks

Types of Padlocks

   Several types of padlocks are available on the market, each with its unique design and locking mechanism. The basic padlock types include:

1. Key-Operated Padlocks

   Key-operated padlocks are the most traditional type of padlock and are opened with a key. The key is used to unlock the shackle, which can then be passed through an eyelet or hasp and locked to secure an object. Key-operated padlocks are available in various sizes and materials. They can provide a high level of security, depending on the design and construction of the lock.

2. Combination Padlocks

   Combination padlocks are opened using a combination of numbers or letters instead of a key. The combination is entered into a dial or a series of buttons on the lock. The shackle is released once the correct combination has been entered. Combination padlocks are convenient and do not require the carrying of a key. But they can be vulnerable to guessing or cracking if the combination is not kept confidential.

3. Digital Padlocks

   Digital padlocks use an electronic mechanism to lock and unlock the shackle. They can be opened using a keypad, a smart card, or a biometric scanner, depending on the design of the lock. Digital padlocks offer high levels of security and convenience. They are often used for applications requiring a high level of access control.

4. Cable Padlocks

   Cable padlocks are similar to traditional padlocks but have a flexible cable attached to the shackle, allowing the lock to secure objects that are not easily accessible with a standard padlock. Cable padlocks are often used to secure bicycles, gates, and other objects requiring longer reach.

5. Laminated Padlocks

   Laminated padlocks are made from multiple layers of metal, each layer being a different thickness and hardness. This design provides enhanced strength and durability and makes it more difficult for a potential attacker to cut or break the lock. Laminated padlocks are often used in high-security applications and are available in key-operated and combination varieties.

6. Weather-Resistant Padlocks

   Weather-resistant padlocks are designed to be used in outdoor or harsh environments. They are made from materials that can withstand exposure to the elements. They are often coated with a rust-resistant finish and are available in various sizes and styles.

7. Shutter Padlocks

   Shutter padlocks are designed specifically for use with roller shutter doors and gates. They have a long, flat shackle that fits into a hasp on the door or gate and can be locked in place to secure the door or gate. Shutter padlocks are available in a range of sizes and materials, including heavy-duty steel for high-security applications.

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Who invented Padlocks?

Who invented Padlocks

   The history of locks dates back thousands of years, and the exact origin is still being determined. The Egyptians and Romans developed some of the earliest known locks. The ancient Egyptians used wooden locks secured with bolts and simple mechanisms for opening and closing the lock.

    In medieval Europe, locks became more sophisticated and were made from iron. Blacksmiths developed locks with keys and wards, preventing the lock from opening unless the correct key was inserted.

   Locks were likely invented and developed independently by different civilizations throughout history. The modern lock as we know it today, with its various components and mechanisms, was developed over many centuries through the contributions of countless individuals and cultures.

2000 BCGAncient EgyptiansDeveloped the first pin-and-tumbler locks made entirely from wood
1778Robert BarronDeveloped the double-acting lock
1784Joseph BramahPatented the high-security Bramah lock and offered a reward of 200 guineas to anyone who could crack it
1818Jeremiah ChubbDeveloped the detector lock that jams when someone tries to open it, making it obvious that it has been interfered with
1846Edwin CottrillCreated the “power proof” and “unpickable” Climate Detector Lock using a variation of the Bramah design
1857James SargentInvented combination locks and the bank time safe
1860Linus YaleDeveloped the convenient pin-tumbler Yale lock
1924Harry SorefDeveloped the secure modern padlock


About Padlocks, how do I change the combination on my combination padlock?

   The process for changing the combination on a combination padlock will vary depending on the specific model of the lock. Most combination padlocks have a reset button or a specific combination that can be entered to change the combination. Refer to the manufacturer’s instructions for your specific padlock for detailed instructions on changing the combination.

How do I unlock a padlock if I have lost the key?

   If you have lost the key to your padlock, you may be able to have a locksmith cut a new key for you. You can also use a shim or a lock-picking tool to open the lock. However, this should only be attempted if you have experience with locks and are confident in your ability to do so without damaging the lock. Sometimes, it may be necessary to drill the lock to open it.

Can padlocks be picked?

   Yes, padlocks can be picked, although the difficulty and success rate will vary depending on the specific type and design of the lock. Higher-security padlocks are designed to be more resistant to picking, while lower-security padlocks may be easier to pick.

How do I keep my padlock from freezing in cold weather?

   In cold weather, padlocks can freeze due to condensation or moisture that gets into the lock. To prevent this, try to keep the lock as dry as possible, and store it in a warm, dry place when not in use. If the lock does freeze, try using a heat source, such as a hair dryer, to warm the lock and melt any ice.

Can I use a padlock to secure my bike?

   Yes, padlocks can be used to secure a bike. However, the type of padlock and the method of securing the bike will depend on the specific requirements of the bike and the location where it is being secured. Cable and laminated padlocks are often used to secure bikes. It is important to ensure that the lock and the bike are secured to a solid, immovable object to prevent theft.

Can I use a padlock to secure a gate or door?

   Yes, padlocks can be used to secure a gate or door. Although the type of padlock and the method of securing the gate or door will depend on the specific requirements of the gate or door and the location where it is being secured. Shutter padlocks and laminated padlocks are often used to secure gates and doors. It is important to ensure that the lock and the gate or door are secured to a strong object to prevent robbery.

Can padlocks be broken or cut?

   Yes, padlocks can be broken or cut. However, the difficulty and success rate will vary depending on the specific type and design of the lock. Higher-security padlocks are designed to be more resistant to cutting and breaking. In contrast, lower-security padlocks may be easier to break or cut. It is important to choose a padlock that is suitable for the level of security required for the specific application.

Wrapping up

   Padlocks are a versatile and portable type of lock that can be used for various purposes, from securing personal belongings to securing large commercial premises. They come in various designs and styles, with different locking mechanisms to suit different requirements and preferences.

   Whether you need a simple key-operated lock for your locker or a high-security digital padlock for your gate, there is a padlock to suit your needs. By understanding how a padlock works and the different types of padlocks available, you can choose the right lock for your specific requirements and ensure that your property is secure.

   Hopefully, you know how a padlock work. You can share it with your family and friends so that they also know about this lock-working mechanism. If you still have questions, contact us. Have a great day!


Combining his passion for security and technology, Joseph is dedicated to providing reliable and affordable combination padlocks to help protect your valuables. With years of experience in the industry, Joseph brings his expertise to to ensure your peace of mind.

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