Home Improvement

What Is a Mortice Lock: All You Need to Know

In the world of door security, the mortice lock stands as a reliable guardian, providing a robust and effective means of safeguarding homes and businesses alike. If you’ve ever wondered:

  • How it works;
  • What are the types and specifics of different mortice locks;
  • Where to install them.

Then read along, and you will learn all that plus more…

What exactly is a mortice lock?

Here is the mortice lock explained in a nutshell: it’s a lock that is inserted into a mortice (a cavity or recess cut into the edge of a door). This makes the whole contraption more robust and less susceptible to tampering.

As far as structure goes, the mortice lock has a keyhole, a cylinder and a bolt mechanism. This mechanism can be a latch bolt or a deadbolt, but regardless of which it is, the mortice lock works like any other. You put the key in and turn. This action retracts the latch bolt or deadbolt, allowing the door to be opened. When the door is closed, releasing the key causes the latch bolt to extend, holding the door shut.

Now that the question of “what is a mortice lock” is answered, let’s see what are the advantages and disadvantages you need to be aware of.

Pros of mortice locks

  • Enhanced security – Mortice locks offer a higher level of security due to their design and placement within the door. They’re used both for residential and office buildings for this very reason;
  • Durability – These locks are more durable and resistant to tampering compared to surface-mounted locks;
  • Aesthetic appeal – Mortice locks are often considered more aesthetically pleasing since they are installed within the door, maintaining a clean and discreet appearance.

Cons of mortice locks

  • Installation complexity – Installing a mortice lock requires creating a cavity (mortice) within the door, which can be more complex and time-consuming unlike surface-mounted locks;
  • Professional installation – Due to the complexity of installation, it’s recommended to have a professional locksmith install a mortice lock;
  • Potential door modifications – Depending on the door’s design, installing a mortice lock might necessitate modifications to the door itself, which could impact its structural integrity or appearance.
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Types of mortice locks

Today’s market offers different types of mortice locks, each designed to fulfil specific security and functional requirements. The two common types are the sashlock and the deadlock.

Additionally, there’s a distinction between 3-lever and 5-lever mortice locks, but more on that later. For now let’s see what is the difference between a sashlock and a deadlock.


What is a mortice sash lock? It’s a type of mortice lock that combines a latch bolt with a deadbolt, offering both security and the convenience of a latch.

How does a sashlock work? The latch bolt can be retracted using the door handle or knob, allowing the door to be opened and closed without requiring a key. The deadbolt is operated using a key, providing enhanced security by extending deeper into the door frame.

Important specifics: Sashlocks are commonly used on doors that require both security and privacy, such as front doors and internal doors in residential or commercial settings.

Where to use? Sashlocks are suitable for external doors, as well as interior doors where an additional level of security is desired, such as office doors or bedroom doors.

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What is a mortice deadlock? A deadlock is a straightforward mortice lock that consists solely of a deadbolt, prioritising security over convenience.

How does a deadbolt work? Deadlocks operate exclusively using a key. When the key is turned, the deadbolt extends into the door frame, providing a high level of security.

Important specifics: Deadlocks are robust and offer a higher degree of resistance against forced entry due to their single-point locking mechanism.

Where to use? Deadlocks are commonly installed on doors that require a higher level of security, such as front doors, storage rooms, and entrance doors in commercial properties.

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What’s the difference between a 3- and 5-lever mortice lock?

You might have heard that these locks come with a different number of levers, but what is the difference between a 3 and 5 lever mortice lock? Well, the number of levers refers to the internal locking mechanisms that the key must engage to operate the lock. The primary difference between 3 and 5-lever mortice locks lies in their security levels.

  • 3-lever mortice lock – This type of lock has three levers and provides basic security. It is typically used for internal doors where high security is not a primary concern.
  • 5-lever mortice lock – A 5-lever mortice lock offers higher security due to the additional levers, making it more resistant to picking and other forms of unauthorised access. This type of lock is commonly used for external doors and doors that require a higher level of protection.

How to identify a 5-lever mortice lock?

Here is how to identify a 5 lever mortice lock from a 3 lever one.

  1. Check the faceplate – Examine the edge of the door where the lock is installed. A 5-lever mortice lock typically has a faceplate with the manufacturer’s name or logo, as well as information about the lock’s specifications.
  2. Count the levers – To identify a 5-lever mortice lock, you need to count the number of levers within the lock mechanism itself. Remove the lock cover or escutcheon to access the internal components. A 5-lever mortice lock will have five levers within the lock body.
  3. Look for certification marks – Many high-security locks, including 5-lever mortice locks, carry certification marks or labels. These marks indicate that the lock meets certain security standards set by relevant authorities. Look for symbols such as the British Standard Kitemark or other certification marks that validate the lock’s security level.
  4. Check the lock documentation – If you have access to the lock’s documentation, such as the user manual or installation guide, it should specify the number of levers and the security features of the lock. This can help confirm whether your lock is a 5-lever mortice deadlock.
  5. Consult a professional – If you’re unsure about the type of lock you have, consider consulting a professional locksmith. Locksmiths are experienced in identifying different types of locks and can provide accurate information about your lock’s security level.

Wondering if your place is set with high-security locks? Not sure if you can identify it? Contact a professional locksmith for a check-up.

Choosing the right mortice lock for your needs

Selecting the appropriate mortice lock is a crucial decision that affects both the security and functionality of your doors. Several key factors should be taken into consideration to ensure you choose the right mortice lock for your specific requirements:

  • Security requirements based on location/type of property – Different properties and areas within properties have varying security requirements. For instance, a front entrance door to your home may need a higher level of security compared to an internal closet door. Assess the crime rate in your area, the potential risk factors, and the value of the items being protected behind the door. Opt for a mortice lock with security features that match the level of protection needed.
  • Size compatibility with existing doors – The size of the mortice lock is crucial for ensuring proper installation and functionality. Measure the dimensions of your door carefully, paying attention to the depth and width of the mortice pocket. Refer to the manufacturer’s guidelines or consult with professionals to determine the correct size of the mortice lock required. Choosing a lock that fits seamlessly within the door ensures proper operation and minimises the risk of installation issues.
  • Professional installation vs. DIY – Decide whether you’re comfortable installing the mortice lock yourself or if you should seek professional assistance. While some mortice locks may come with installation instructions, the complexity of the process can vary. If you’re uncertain about the door lock fitting process, it’s advisable to enlist the services of a qualified locksmith. Professional installation ensures that the lock is correctly fitted, maximising its effectiveness and lifespan.
  • Additional security features – Evaluate the additional security features offered by the mortice lock. Some locks come with anti-drill plates, anti-saw pins, and anti-pick mechanisms, which enhance their resistance against common forced entry techniques. If security is a top concern, consider locks that offer these supplementary features.
  • Brand reputation and certification – Opt for mortice locks from reputable brands known for their quality and security standards. Some popular and commonly sought brands in UK are Yale, Chubb, ERA.  Look for locks that carry certification marks such as British Standard Kitemarks or other industry-recognized approvals. These marks indicate that the lock has undergone rigorous testing and meets certain security criteria.
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How much does it cost to fit a mortice lock?

The cost of fitting a mortice lock can vary based on several factors, including the type of lock, location, complexity of installation, and the locksmith’s fees. When you google the phrase “how much to fit a mortice lock” you will get around £125 for the UK, and that’s fair. This cost could include the lock itself, labour, and any necessary materials for installation.

Factors affecting the price

  1. Type of mortice lock – Different types of mortice locks come with varying levels of complexity. A basic lock installation might cost less than installing a high-security lock with additional features.
  2. Locksmith’s experience and reputation – Established locksmiths with a strong reputation may charge higher fees due to their expertise and quality of service.
  3. Location – Locksmith prices can differ between regions due to varying living costs and demand for services.
  4. Time of service – Emergency or out-of-hours services might incur additional charges.
  5. Lock complexity – Some locks have intricate mechanisms, requiring more time and skill to install. High-quality locks or those with advanced security features can cost more.
  6. Additional materials – Depending on the door’s condition and the lock’s requirements, additional materials such as spacers, screws, or reinforcing plates might be needed.
  7. Travel distance – If the locksmith needs to travel a long distance to reach your location, it could affect the overall cost.
  8. Service fees – Some locksmiths charge call-out fees or minimum service charges in addition to the lock installation cost.
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Rely on an experienced locksmith for adequate lock installation

When it comes to the security of your home or business, proper lock installation is non-negotiable. At Fantastic Services, we take pride in offering reliable locksmith services that ensure your property’s safety.

The team of skilled professionals we work with are familiar with the specifics of different locks and manufacturers. They are also dedicated to delivering exceptional lock installation results, providing you with peace of mind and the assurance that your home’s security is in capable hands.

Don’t worry if your lock just broke!

Get in touch with experienced locksmith today!

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  • Mortice locks provide higher security due to their robust design;
  • Installing mortice locks can be intricate and time-consuming compared to surface-mounted locks;
  • There are two primary types of mortice locks discussed – sashlock and deadlock;
  • The cost of installing this lock can vary based on lock type, location, installation complexity, and locksmith fees.
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