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Door lock components

Understanding the Parts of a Door Lock

Your home’s security starts with understanding the fundamental components of your door locks. Each part is vital in keeping your family and belongings safe, from the sturdy bolts and intricate cylinders to the precise strike plates and latch mechanisms.

Knowing how these elements work together empowers you to troubleshoot minor issues and guides you in making informed choices when upgrading your home security.

Remember, if you’re having problems with a sticky or faulty door, knob, handle, or lock, trust the skilled locksmiths at Great Valley Lockshop to help.

Key Takeaways

1. Common parts of a door handle and lock include essential components like cylinders, bolts, boxes, and strike plates, which ensure security and functionality.

2. Knowing the names and functions of door lock components empowers homeowners to troubleshoot issues, perform maintenance, and make informed decisions when upgrading or replacing locks, thereby enhancing overall home security and peace of mind.

3. Great Valley Lockshop specializes in comprehensive lock services, offering expert advice and installations across Pennsylvania, Delaware, Maryland, and New Jersey, ensuring top-notch security solutions tailored to your needs.

What Are the Parts of a Door Lock and Handle Called?

Understanding the components of a door lock and handle is essential for both security and functionality. Whether you’re upgrading your home security, performing maintenance, or simply curious, knowing each part’s name and function can be invaluable.

Door locks and handles are comprised of various parts, from the visible handles and knobs to the internal mechanisms that ensure the door stays securely closed. In this guide, we’ll break down each component, explaining their roles and how they work together. With this knowledge, you’ll be better equipped to choose, install, and troubleshoot door locks effectively.

Below, we break down the labeled parts of a door lock and handle.

Diagram showing the parts of a door lock, including the knob, rose, cylinder, latch assembly, bolt and strike plate.

Parts of Door Lock Diagram showing the knob, rose, cylinder, latch assembly, bolt and strike plate.

Door Handle Parts


  • Handle: Typically lever-style, designed to be pushed down or lifted to operate the latch. Common in modern and commercial settings due to their ease of use, especially for people with disabilities.
  • Lever: A type of handle that is straight or slightly curved, providing better grip and leverage.
  • Knob: A round or spherical handle that requires turning to operate the latch. Common in residential settings but less ergonomic than levers.


A circular or oval plate that surrounds the base of the handle or knob. It hides the internal mechanism and any mounting screws. Rosettes come in various designs and finishes to match the decor.

Escutcheon Plate

A larger plate that can also cover keyholes or privacy locks. Often used in more decorative or traditional designs. It serves both aesthetic and protective functions.

Lock Mechanism Parts


The core part of the lock where the key is inserted. The cylinder, or lock body, is the part of the door lock where you insert the key. When it’s locked, the cylinder engages a series of spring-loaded pins which keep the cylinder from turning.

When you insert a key, the uneven edge pushes the pins upward to fit the key’s height in that location within the lock body. Essentially, it recognizes the correct key when the pins move into their proper places. This “opens” the cylinder, allowing the bolt to move, and you to open the door.


The part of the cylinder that rotates when the correct key is inserted and turned. It is the central piece within the cylinder, housing the keyway and interacting with the pins.

Pins and Springs

  • Pins: Small metal pieces inside the cylinder. They come in two parts: driver pins and key pins. The key pins align with the cuts on the key, while the driver pins are pushed by the springs.
  • Springs: Tiny coils that push the pins into position. When the correct key is inserted, the pins align perfectly, allowing the plug to turn.

Strike Plate

A metal plate attached to the door frame. The bolt extends from the cylinder into a small square shaped hole—this is the “box”. It is designed to hold the bolt securely in the doorframe when the lock is engaged.

The metal plate, which attaches to the frame of the door, is the strike plate. The purpose of the strike plate is to guide the bolt from the cylinder into the box of the frame and give added reinforcement to the locking mechanism.

It has a hole or holes that align with the latch or deadbolt, allowing them to engage securely. The strike plate reinforces the frame and helps prevent the latch or bolt from being forced open.


A movable bolt that extends into the strike plate to keep the door closed. The lock engages a bolt inside the door. This piece of metal extends from the door into the frame and holds it closed. There are two main styles of latch (or bolt)—a spring bolt and a deadbolt.

  • Spring Bolt – A spring latch is a bolt held in place by a spring clip. The spring is compressed to unlock the bolt, and when released, it snaps into a locked position. This type of door generally locks automatically when closed.
  • Deadbolt – A deadlatch does not have the spring loading mechanism. It can be locked or unlocked at any time using a key or with a knob on one side of the door. Deadbolts are generally considered to be the more secure choice between the two types of bolts, especially when the lock has a deadbolt plunger. The deadbolt plunger (or guardbolt) is smaller and directly next to the deadbolt; its job is to prevent the lock from being picked or ‘jimmied’ open.


Additional Components

  1. Faceplate. The metal plate on the edge of the door where the latch or deadbolt is located. It helps guide the latch or bolt into the strike plate and protects the door’s edge from damage.
  2. Thumb Turn. A small lever or knob on the inside of the door that allows you to lock or unlock the door without a key. Commonly used with deadbolts for convenience.
  3. Keyhole. The opening in the door handle or lock where the key is inserted. The keyhole is designed to match the specific key profile of the lock.
  4. Backplate. A plate mounted on the surface of the door, behind the handle, knob, or thumb turn. It can be decorative and provides additional support and protection for the lock mechanism.
  5. Spindle. The rod that connects the two handles or knobs through the door and operates the latch mechanism. When the handle or knob is turned, the spindle rotates to retract the latch.
  6. Housing. The casing that contains the internal mechanism of the lock. It protects the components from damage and tampering.

Steps on How to Install a Door Lock

Installing a door lock can be an easy task if you have all the needed materials. In addition, the difficulty of the activity will depend on the type of door lock you’re trying to install. More advanced door locks will probably require the help of a locksmith.

Here is a guide on how to install a door lock.

Tools and Materials Needed

  • New door lock set (including latch, strike plate, screws, and keys)
  • Phillips head screwdriver
  • Flathead screwdriver
  • Drill and drill bits
  • Tape measure
  • Chisel
  • Hammer
  • Pencil
  • Safety glasses

Step-by-Step Installation

Steps to install a door lock
  1. Remove old lock. Use a screwdriver to remove the screws from the handle/knob and latch, then carefully remove all parts of the old lock. Ensure the door and frame are clean and free of debris.
  2. Mark new lock positions. Use the template provided with the lock set to mark the door for the new lock’s handle/knob and latch. Common handle heights are about 36 inches from the floor. Align the latch with the edge of the door and mark its position, and do the same for the strike plate on the door frame.
  3. Drill face bore hole. Using a 2 1/8 inch drill bit, drill a hole through the door where the handle or knob will go.
  4. Drill edge bore hole. Drill a 1 inch hole on the edge of the door for the latch.
  5. Chisel latch mortise. Use a chisel to create a recess on the door edge for the latch faceplate, making it deep enough for the faceplate to sit flush with the door edge.
  6. Chisel strike plate mortise. Chisel a recess on the door frame for the strike plate, ensuring it matches up with the latch.
  7. Install latch. Place the latch into the edge bore hole and secure it with screws.
  8. Attach strike plate. Align the strike plate with the hole on the door frame, and secure it with screws.
  9. Attach exterior handle/knob. Insert the exterior handle or knob through the face bore hole, ensuring the spindle passes through the latch.
  10. Attach interior handle/knob. Align the interior handle or knob with the spindle and secure both sides together with the screws provided. Ensure the handles or knobs operate the latch smoothly by turning them.
  11. Insert lock cylinder. If your lock has a key cylinder, insert it into the exterior handle or knob and attach it with the screws provided, making sure it aligns correctly and operates smoothly with the key.
  12. Test lock. Close the door and test the lock by turning the key, handle, or knob to ensure it locks and unlocks smoothly. Adjust the alignment of the latch and strike plate as needed if the lock or latch doesn’t operate correctly.

What Are Common Types of Door Locks?

There are several common types of door locks, each designed for specific applications and varying levels of security. Understanding these types can help you choose the best door lock for your needs.

From simple barrel bolts to sophisticated smart locks, each offers unique features and benefits. This overview will cover the most common types of door locks, explaining their uses and advantages. Knowing these options will enhance your security and convenience.

1. Deadbolts

  • Single Cylinder Deadbolt: Operated with a key from the outside and a thumb turn from the inside. Common for residential use.
  • Double Cylinder Deadbolt: Requires a key for both sides, providing extra security. Often used where there’s a risk of break-ins through windows adjacent to the door.

2. Knob Locks

  • Built into the door knob and commonly used for interior doors. They offer basic security and are often paired with deadbolts on exterior doors.

3. Lever Handle Locks

  • Often used for interior doors in commercial buildings. Easier to operate than knob locks, especially for people with disabilities.

4. Mortise Locks

  • Installed into a pocket cut into the door edge. Known for durability and strength, commonly found in commercial and older residential buildings. They can accommodate various locking mechanisms and functions.

5. Rim Locks

  • Surface-mounted locks installed on the door interior. Used for additional security on external doors or for vintage aesthetics.

6. Keyless Entry Locks

  • Electronic Keypad Locks: Allow entry via a code entered on a keypad. Useful for eliminating the need for physical keys.
  • Smart Locks: Operated via smartphone apps, Bluetooth, or Wi-Fi. Can include features like remote access, integration with smart home systems, and temporary access codes.

7. Cam Locks

  • Commonly used in furniture, cabinets, and mailboxes. Operated with a key, the cam (a metal plate) rotates to lock or unlock.

8. Barrel Bolt

  • A simple latch that slides into a catch on the door frame. Used for internal security, such as bathrooms or bedroom doors.

9. Padlocks

  • Portable locks that can be used with hasps or chains. Available in various sizes and security levels, often used for gates, sheds, and lockers.

10. Sliding Door Locks

  • Specialized locks designed for sliding doors. They can be simple latches or more secure mechanisms that prevent the door from being lifted off its tracks.

11. Chain Locks

  • Chains attached to the door and frame, allowing the door to be opened slightly for viewing or ventilation while maintaining security.

12. Window Locks

  • Smaller locks designed specifically for windows to prevent unauthorized entry. They come in various types, including latch locks, keyed locks, and sliding window locks.
parts of a door knob

Each type of lock serves a specific purpose, offering varying levels of convenience and security. Selecting the appropriate lock depends on the specific requirements of the door and the desired level of security.

Great Valley Lockshop specializes in all kinds of locks. Consult our team of experts to gain insights and we can do the job for you! Our services include Pennsylvania, Delaware, Maryland, and New Jersey. Contact us today!

Latest Trends in Types of Door Locks

Technology has brought vast improvements to home security. In particular, businesses are increasingly interested safeguarding their property by upgrading locks and installing security systems. Electronic locks are just one of the great new options on the market.

Electronic locks are very different from traditional spring or deadbolt style locks. They rely on a series of magnets and small, electric-powered motors that are activated to open and close. Electronic locks are programmed to require the correct keypad combination, key fob, access card or biometric data, such as fingerprints, in order to unlock.

Smart Electronic Locks are electronic locks with the added capability of being controlled remotely through a smartphone application. A business owner can monitor traffic, restrict access through certain doors, lock doors and activate the security system without being anywhere near the building. Usually, smart electronic locks also have a mechanical key cylinder to allow access with a traditional key.

Locksmiths to Install All Parts of a Door Lock Assembly for You

You can rely on locksmiths to install all parts of a door lock assembly for you. They are trained and experienced in handling various types of locks and security systems, ensuring precise installation and optimal functionality.

Their knowledge extends beyond installation to include troubleshooting and ensuring that your locks operate smoothly and securely. Locksmiths can fix door locks for you. Whether you’re upgrading your home security or need a new lock system installed, locksmiths offer professional services that cater to your specific needs and preferences.

If you need to have your locks rekeyed or you’ve decided it’s time to increase security around your home or office, get expert advice on the best solution. Reach out to our team at Great Valley Lockshop in Malvern, PA. We work with customers in the Philadelphia area and all around Pennsylvania, Delaware, Maryland and New Jersey.

Call us at or fill out our online request form to get in touch with Great Valley Lockshop.


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