Small Format Interchangeable Cores, known in the commercial industry as SFIC or more broadly as IC Cores (which can also include large format interchangeable cores or LFIC), are an integral part of most multi-site mechanical key management systems today. But how and why did the oldest known lock in the world — made of wood over 4,000 years ago — become the interchangeable cores that we see in so many commercial doors today?
IC cores are primarily used in commercial settings to offer reliable security and easier manageability. To understand how commercial IC cores have grown to dominate key control in physical security, let’s travel back in time and learn about the development of lock and key systems throughout history. While you may not spend time thinking about the technological advancements that have led to today’s locks and keys, it is only due to innovative minds from days past that we have the security and convenience of today's commercial IC cores.
Who invented locks and keys?
The original locks and keys looked similar to a long wooden toothbrush, and have been around for centuries as an effective way to keep goods, valuables, and people secure. The brush looking keys (also known as levers) would correspond to pins within a wooden housing system to lock and unlock an area. As you can imagine, wooden locks were not very secure or reliable, so innovation continued.
The Romans invented metal locks and keys that featured projections within the lock which allowed a key to be made with corresponding cuts. Roman locksmiths tried to improve the security of their lock and key designs by making them more complex, but the locks were still relatively easy to pick.
In the 1700s, the complexity of locks and keys continued to advance with the creation of a tumbler system. Tumbler locks increased security with multiple levers within the locking mechanism that had to be lifted to a certain height to turn the bolt. This innovation was a turning point in the early security industry, making locks more of a deterrent than a hassle that could be easily picked.
Locksmiths continued to improve the security of the tumbler lock by adding more sensitive pins. While innovation has continued, this system is still used to create the lock and key mechanism that we’re familiar with today in commercial IC cores.
What is an IC Core?
Interchangeable cores (IC Cores) are based on the tumbler locks created in the 18th century. The core is the cylinder that fits into the locking hardware installed in the door. This is where the key is inserted into the lock, and tumblers within the core correspond to the notches visible on the key. The housing of a lock is the additional locking hardware that fits into the door and remains in place when locks are changed or a core is replaced.
IC cores can be removed from the surrounding locking hardware in order to change the lock without needing to remove the door handle or lock housing. The interchangeable core was invented in 1919 by a man named Frank Best.
Frank Best was working as a high school janitor in the early 1900’s when he created the IC core. He was inspired by his own frustrations managing many doors and all the keys that opened them throughout his entire school. Every time a key was lost, a locksmith would have to be called to remove the locking hardware and change the lock. In the early 1900’s, while tumbler locks had made key security much more secure, it was still a specialized field reliant on the knowledge of locksmiths to remove the standard core. Best spent seven years inventing and perfecting the interchangeable core, which could be rekeyed with a control key and without the help of a locksmith.
Innovation in IC Cores
Interchangeable cores are present in almost every commercial lock and key system, from small format interchangeable (SFIC) to large format interchangeable cores (LFIC). IC cores are an integral part of maintaining security for commercial multi-site goods and service locations.
Why are interchangeable cores so popular?
If you manage a large facility (or multiple locations) with many locks and every door handle and locking mechanism had to be removed to update your security, a security breach would be an expensive, time-consuming, and logistical nightmare. IC cores allow facility managers to more easily update security after a key is lost or stolen with considerably less work than what was required of the Romans — and without any locksmith assistance, thanks to Frank Best.
Interchangeable cores are much easier to manage compared to standard cores (which are typically used for residential security and require a locksmith for removal) because they can be removed from the housing with a Control Key. This allows managers to replace IC cores after a security breach without any specialized tools or assistance. Once the core has been removed with the Control Key, a new core can be easily inserted into the housing to re-secure a facility or access point.
Standard Format vs. Large Format Interchangeable Cores
IC cores come in different sizes for different commercial uses. Small format IC cores (SFIC) are more universal than Large Format IC cores (LFIC) and Full Size IC cores (FSIC). Typically, the lock housing for SFIC are cross-compatible, meaning that a core from one manufacturer can often be used with housing from a different manufacturer. SFIC-associated keys have a smaller profile than keys associated with large format or full size cores.
User-Rekeyable IC Cores
While interchangeable cores simplified the rekeying process by eliminating the need for professional assistance, the innovation process has continued in the 21st century in order to address two of the biggest frustrations associated with IC cores — storage and management cost. Most commercial facilities have many doors, access points, and key holders. In the event of a rekey, you need to have key cores waiting in storage so that they’re easily accessible when addressing a security breach. Depending on the size of your facilities, you could be storing a considerable number of cores and associated keys. If you don’t have adequate storage or fall behind when reordering cores, you’re left waiting on the manufacturer to ship new IC cores to you. Additionally, the cost of replacing cores each time a key goes missing can become very expensive, very quickly.
To address the frustrations of large-scale rekeying, InstaKey developed a new IC core in the 1980’s. Rekeyable IC cores are similar to traditional IC cores as they can be easily removed from the lock housing without professional assistance. But with rekeyable functionality, managers don’t have to remove the core to rekey. Each rekeyable IC core allows up to nine step changes, meaning that the same core can be rekeyed nine times before having to be swapped out.
Rekeyable cores work with a Step Change Key, which is used to shear off a wafer inside of the core, recombinating it without needing to remove it from the housing. Each set of rekeyable cores comes with a Rekeying Kit that includes a Step Change Key and the replacement keys needed after the rekey. Having cores that can be rekeyed many times without ever needing to be removed from the locking hardware can significantly impact the number of cores that you need on-hand in storage. Rekeying with rekeyable cores also allows you to reduce costs as well by only purchasing the replacement keys needed instead of purchasing a new core and keys each time.
Locks and keys have come a long way since the wooden versions used 4,000 years ago. Innovations in IC cores have made key management for modern organizations easier and more cost-effective than ever before. Implementing effective key control for your organization can save you time, money, and enhance security. Consider InstaKey's user-rekeyable IC cores to see how we can help your facilities be at the forefront of commercial core innovation and eliminate the time and hassle of core swaps.