
Why Keys Snap Inside Locks and Cylinders
Keys break inside locks for reasons that are almost always mechanical and preventable in hindsight. A worn key that has been duplicated several generations from the original gradually loses structural integrity, especially at the bow-to-blade junction. Applying lateral pressure while turning — something people do instinctively when a lock is stiff — concentrates stress right at that weak point and the blade snaps cleanly. Temperature swings that Henrico County experiences through the year also play a role: the freeze-thaw cycles of a Richmond-area winter cause cylinder pins to bind, and forcing a cold, slightly bowed key through a sluggish cylinder is a reliable recipe for a break. Mortise lock cylinders, which are common on older colonial-style homes in the Lakeside and Bon Air neighborhoods as well as on commercial storefronts, are particularly susceptible because the cylinder sits deeper in the lock body, meaning a broken fragment has nowhere obvious to go.
Corrosion is another major culprit. A cylinder that has not been lubricated in years develops internal friction that a key must fight on every turn. Eventually the blade cannot handle the torque. Vehicle ignitions present a similar picture: a worn wafer stack inside the ignition lock can grip a key unevenly, and any sudden jerk to free a stuck key causes it to shear. Understanding why a key broke is part of what our technicians assess on arrival, because it informs whether the cylinder itself needs servicing or replacement after extraction — and that determination is always shared with you before any additional work begins.
