How Master Keying Works: Common Pitfalls and Best Practices | Oliphant Lock and Safe
A master key system allows certain keys to open several locks, while still letting you have separate keys for individual doors. It works using a standard pin tumbler design. Inside the lock, small pins determine which key can turn the plug. In a regular lock, bottom pins are pushed down by drivers. The cuts on your key match the heights of these pins. When the right key is used, the tops of the bottom pins line up with the shear line, so the plug can turn.
Master-keyed locks work a bit differently. A locksmith adds master wafers between the bottom pins and the top drivers, which creates a second shear line. This means the cylinder can turn at two different pin heights. The master key raises the pins to one height, while the change key raises them to another. Both keys can open the lock.
Common Master Key Mistakes
If the math is off, your security can suffer. Sometimes, a key might open a lock it shouldn’t—locksmiths call these ghost keys. Each extra master wafer increases the number of keys that can work. A cylinder with lots of wafers is easier to pick and accepts more key cuts than intended. Security goes down as convenience goes up, so you need to find the right balance.
Putting too many wafers in a cylinder can cause mechanical problems. When there are too many, you have to use short bottom pins, which can flip sideways or get stuck. Complex cylinders also collect debris faster, which can make the lock fail. If the system isn’t planned well, you might run out of unique key codes and have to repeat them, which weakens security.
Managing Key Control and Hierarchy
Keeping detailed records is key to building security. Guessing during cylinder pinning doesn’t work. Use a standard progression chart to track every code you use and avoid duplicates. Design your system from the top down: start with a Grand Master Key, then create Master Keys for each department, and finally assign Change Keys to individual offices.
Keep your key hierarchy simple, since complicated systems can lead to mistakes. Store your records safely, because losing them means you’ll have to re-key everything, which is expensive. Regularly check who has each key. Using patented keyways also stops hardware stores from making copies, giving you extra legal and physical protection.
Secure Your Facility with Oliphant Lock and Safe
Master key systems need careful planning. If the pinning isn’t done right, your property could be at risk. We design systems that work properly, handle all the math and installation, and keep your records in order. Contact Oliphant Lock and Safe if you need help with your key system.
Image credit: // Shutterstock // Andrii Anna photographers
