Small Format Interchangeable Cores (SFIC) are perhaps the most popular style of lock in history. They're so prevalent that nearly every cylinder manufacturer has their own version of a SFIC on the market in effort to capture a piece of the SFIC business. Some of the more elaborate offerings feature patented key control, allowing existing SFIC users to protect against unwanted key duplication without having to replace large amounts of existing hardware. These cylinders have always been limited by the size of the master key systems they can support.
Master Key Potential
A master key system built on 6-pin cores is capable of only 4096 unique changes, and a 7-pin system tops out at 16,384. Those numbers are far too small for many office complexes, universities, and government entities that have large, multiple-building campuses, forcing the use (and management) of many different sectional keyways for large installations. The new KeyMark X4 retrofit cylinder line from Medeco High Security Locks adds another dimension to previous SFIC offerings. The KeyMark X4 product line incorporates the tried-and-true Best A2 pinning specification, and adds a locking pin and slider that is actuated by a special key side bitting. The addition of these components quadruples the amount of possible key combinations, allowing for much larger master key systems than the majority of SFIC products on the market. A 6-pin KeyMark X4 master key system has the capacity for up to 16,384 theoretical changes, while a 7-pin system can be as large as 65,536. Another way to look at it is that the extra changes available in a KeyMark X4 master key system are equivalent to having an additional pin chamber. There are a number of different sliders with varying dimensions that are used specific to the keyways or master key systems. There is a single locking pin that is used with all slider variations. You may consult the Medeco factory for further information.
Like the first generation KeyMark by Medeco, the x4 product line will allow the integration of SFIC and conventional cylinders (KIK, rim, mortise) into one keying system. KeyMark x4 is available to retrofit more different types of locking hardware than any other brand. Many brands that have a SFIC retrofit do not also have conventional type cylinders available, or the cylinders are not able to utilize the same keys and/or pins.