The Ultimate Guide to Choosing the Best Interchangeable Core

Key Takeaways

  • When choosing the best interchangeable core lock, consider compatibility, security, key control, durability, ease of use, and cost.
  • Medeco’s SFIC system is a top-of-the-line option that offers exceptional security and patented key control technology, making it virtually impossible to duplicate keys without proper authorization.
  • ASSA ABLOY’s Twin Series SFIC and Schlage Everest 29 are reliable options that offer exceptional security, key control, durability, compatibility, and customizability.

Before making any purchase, please go through my recommendation process here to see how I recommend products.

Are you in the market for a new lock to secure your business, home, or property? If so, you might be considering an interchangeable core lock. These types of locks are becoming increasingly popular among business owners and homeowners alike, thanks to their enhanced security features and flexibility. 

Recently, my friend bought a warehouse on rent for his business, and I helped him choose an interchangeable core lock to ensure his property was secure. After seeing the benefits firsthand, I decided to put together this guide to help others make an informed decision when selecting the best interchangeable core lock for their needs. 

In this blog, we’ll cover the top interchangeable core locks on the market, highlighting their unique features, pros and cons, and overall value.

What Are Interchangeable Lock Cores?

What Are Interchangeable Lock Cores?

An interchangeable lock core is a type of lock cylinder that can be easily removed and replaced without having to replace the entire lock. This makes it possible to rekey the lock, which means changing the key that opens the lock without having to replace the entire lock hardware.

Interchangeable lock cores are commonly used in commercial buildings, schools, and other settings where there are multiple locks that need to be keyed alike or where keys need to be changed frequently. They are also popular among landlords and property managers who need to quickly and easily change the locks when tenants move out.

The interchangeable lock core is made up of a cylinder, which contains the keyway and the pins that match the key, and a housing that surrounds the cylinder and is fixed to the lock hardware. The cylinder can be easily removed from the housing by inserting a control key and turning it to release the cylinder. Once the cylinder is removed, it can be replaced with a new cylinder that has a different keyway and pins to match a new key.

Factors to Consider When Choosing A Interchangeable Core

Factors to Consider When Choosing A Interchangeable Core

When we were looking for IC for the warehouse, we considered the following factors. We felt that these factors are important while making the decision. 


The first thing that we checked was the compatibility. You want to make sure that the core you choose is compatible with your existing lock. Otherwise, you’ll have to replace the entire lock, which defeats the purpose of having an interchangeable core.


Needless to say, security is an important factor to consider. When it comes to lock cores, the concept of security means features like pick-resistance and bump-resistance key systems, hardened steel bolts, and patented key control systems.


Next factor that we considered was the durability of the lock core. Since the lock was to be put in the warehouse, a high usage area, we wanted the core to withstand the wear and tear. For us, durability means that the body of the core is made of tough material like steel or brass.

Ease of Use:

Ease of use is important. You want a lock core that is easy to install and remove without the help of a professional. Look for locks with easy installation processes and simple key systems.


Finally, our last factor was the cost. We didn’t want to splurge too much yet didn’t want to compromise on the security. We didn’t want to go above $100.

Reviewing The Best Interchangeable Core Locks

These are some of the options that we considered when we were making our purchase.

Medeco KeyMark X4 SFIC (Personally Bought)

Medeco KeyMark X4 SFIC

When my friend rented a warehouse for his business, he wanted to ensure that the property was secure from unauthorized entry. After researching various options, we decided to go with Medeco’s SFIC (Small Format Interchangeable Core) system – a top-of-the-line option that offers exceptional security.

The patented key control technology of Medeco’s SFIC system is truly impressive. With this technology, only authorized personnel have access to the system, making it virtually impossible to duplicate keys without proper authorization. This makes it the perfect choice for high-security environments where key control is critical.

What’s more, the SFIC system is highly customizable, with a range of cylinder options and keyways to choose from. This addressed our compatibility factor. 

Since the core body is made of brass, we didn’t have to think twice about its durability. It came with 2 keyed alike operating keys and 1 control key. 

Priced at $89, Medeco’s SFIC system just fell under our budget range making it the best IC core choice for us.


  • Advanced key control technology 
  • Highly customizable with a range of cylinder options and keyways
  • The dual-locking mechanism provides exceptional protection against unauthorized access
  • Suitable for a wide range of hardware and applications


  • More expensive than some other options on the market

ASAA ABLOY Max+E SFIC (Tried And Tested)


The ASSA Max+E SFIC is a highly respected and reliable option in the world of high-security locking systems. It boasts several benefits, such as its high level of security, key control, durability, compatibility, and customizability, making it an ideal choice for many environments.

One of the primary benefits of the Twin Series is its high level of security. Its patented technology makes it extremely difficult to pick or bypass, and its two sets of pins provide an extra layer of protection against manipulation, making it an excellent choice for environments where security is a top priority.

Additionally, the Twin Series offers exceptional key control with a restricted keyway that prevents unauthorized duplication of keys. This level of key control is essential for organizations that need to protect sensitive information or valuable assets.

Moreover, the Twin Series is built to last with high-quality stainless steel and construction that can withstand heavy use and abuse, making it a reliable choice for high-traffic areas or environments where locks may be subject to rough handling. It is also highly compatible, designed to work with a wide range of hardware and applications, and highly customizable to meet the specific needs of the user.

However, one shortcoming of the Twin Series is its cost. It is more expensive than some other options on the market, making it a less desirable choice for those on a tight budget.


  • Exceptional key control with a restricted keyway to prevent unauthorized duplication
  • Durable construction to withstand heavy use and abuse
  • Highly compatible with a wide range of hardware and applications


  • More expensive than some other SFIC options

Schlage Everest 29

Schlage Everest 29

The Schlage Everest 29 interchangeable core is a high-security lock cylinder that is designed to provide maximum protection against picking, drilling, and other forms of forced entry. The Everest 29 is part of the Schlage Primus XP line of locks, which is recognized as one of the most secure and reliable locking systems on the market today.

The Everest 29 features a unique keyway design that is virtually impossible to duplicate, making it highly resistant to unauthorized key copying. It also uses a patented sidebar technology that provides additional protection against picking and bumping. With its 7-pin design, the product offers a significantly larger number of keying combinations in a master key system compared to 6-pin cylinders, with a four-fold increase in the available combinations.

One of the key benefits of the Everest 29 is its ability to be easily rekeyed without having to disassemble the lock. This is possible thanks to the interchangeable core design, which allows for the core to be removed and replaced with a new one in a matter of seconds. This feature is especially useful in commercial and industrial settings where security needs may change frequently.

While I found this lock an outstanding option, my friend did not need this high level of security, so we did not invest in this one.


  • High level of security against picking, drilling, and unauthorized key copying
  • Patented sidebar technology provides additional protection against picking and bumping
  • Compatible with a wide range of locks, including those from Schlage and Falcon, as well as many locks from other manufacturers.


  • More expensive than some other options on the market
  • Not ideal for residential use unless a high level of security is necessary

Best Access SFIC (Heard About It)

Best Access SFIC

The Best Access Systems SFIC is a reliable and affordable option for those looking for a straightforward and easy-to-install interchangeable core system. I heard about it from one of my fellow lock enthusiasts while I was researching the best interchangeable core. 

One of the standout features of the Best SFIC is its easy installation process. The system is designed to be user-friendly, and it can be installed quickly and easily by those with limited locksmithing experience. This makes it a great option for DIYers or those looking to save money on installation costs.

In addition to its ease of installation, the Best SFIC is also highly compatible. It is designed to work with a wide range of hardware and applications, making it a versatile choice for a variety of settings. It can be used with mortise locks, rim locks, and other types of hardware, making it a flexible option for those who need to secure different types of doors.

While it may not offer the same level of customizability as some other systems, it does offer a range of keyways and cylinder options to choose from. This allows users to tailor the system to their specific needs and preferences. However, if you require more customization options, other high-end systems may be a better choice.

In terms of security, the Best SFIC offers good protection for an affordable price. While it may not offer the same level of security as some higher-end systems, it is still a reliable choice for those on a budget. However, if security is a top priority and budget is not a concern, it may be worth investing in a higher-end system with more advanced security features.

Overall, the Best Access Systems SFIC is a solid and easy-to-use system that offers decent security and versatility for an affordable price.


  • Easy to install with a user-friendly design
  • Compatible with a wide range of hardware and applications
  • An affordable option for those on a budget


  • May not offer the same level of customizability as some other systems
  • May not offer the same level of security as some higher-end systems

Frequently Asked Questions

  1. How do interchangeable core locks work?

Answer. Interchangeable core locks consist of two parts: the core and the shell. The core is the part that contains the locking mechanism and can be easily removed and replaced without having to disassemble the entire lock. The shell is the outer part of the lock that houses the core.

  1. Is maintaining interchangeable core locks challenging?

Answer – Like any other lock system, interchangeable core locks require regular cleaning and lubrication to ensure that they continue to function properly. Additionally, if any part of the lock becomes damaged or worn, it will need to be repaired or replaced to maintain the security of the system.


Choosing the best interchangeable core for your locks is an important decision that requires careful consideration. The key factors to consider include the level of security you require, the type of keyway system you prefer, the ease of installation, and the compatibility with your existing lock hardware. Ultimately, the right interchangeable core will depend on your individual needs and preferences. By taking the time to research and evaluate your options, you can make an informed decision that will provide the security and convenience you need.

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Hey! I am Mark. Though I am not a locksmith by profession, but locks have always fascinated me since my teens. And it all started when I got locked out of my house and I had to pick the lock. Since then it has become my hobby to learn more about different kinds of locks, understand their working and methods to pick them up. In due course of time, I have also become better aware of how installing the right lock goes a long way in ensuring iron clad security. I aim to share my passion (about locks) through this blog. If you are also passionate about picking locks or are just looking to beef up the security, hop on the ride.