The Complete Handbook of Key Caps

Chapter 1: Understanding Key Caps

A Component People Overlook

A key cap is the plastic, rubber, or metal shell that fits over the head or bow of a key. It is not a decorative accessory, though it can be that too. It is a functional part of the key system that affects grip, durability, identification, and even whether the key works at all in certain locks. For the professional who specifies or maintains locks, the key cap is a decision point that gets skipped far too often, mostly because it is cheap and easy to take for granted. But that cheap part is exactly where keys bend, break, or fail to operate, and where a facility loses time and money.

Consider a typical commercial building with 200 keys on a master key system. The facility manager buys a bulk pack of generic key caps, snaps them onto the keys, and hands them out. Three months later, a maintenance worker reports that his key will not turn in a door lock. The locksmith inspects it and finds the cap has rotated on the key bow, so the user is gripping a cap that is no longer aligned with the blade. The user forces the key, the blade twists at the shoulder, and the key snaps off in the cylinder. The cylinder has to be disassembled, the broken key extracted, and a new key cut. That one cheap cap cost the building a service call, a replacement cylinder, and a day of