Dimple Locks: Bitting on the Key Face
A dimple lock is a pin tumbler variant where bitting appears as round dimples on the broad faces of the key blade rather than along the edge. The keyway is often oriented perpendicular to the pin stacks, and many dimple keys insert in either orientation — a convenience feature that also looks distinctly high-tech.
Manufacturers like KABA, Mul-T-Lock, DOM, and EVVA built reputations on dimple platforms with restricted keyways, side pins, telescoping pins, and sidebar systems. The format is common across Europe and in commercial high-security specifications worldwide.
Principles of Operation
Functionally, dimple locks behave like pin tumblers: springs, drivers, and key pins must align at the shear line. The difference is geometry — dimples on the blade face engage pins radiating from multiple directions. Advanced models add sidebars, axial rotation elements, and moving parts inside the key itself.
Pin Count vs. Key Length
Traditional edge-cut keys grow unwieldy beyond seven or eight pin stacks — long keys bend and break. Dimple locks distribute pins around the blade perimeter, adding positions without extending key length. Depth options per pin are fewer (often two to six) because blade thickness limits travel.
High-Security Features
Restricted key profiles, active and passive side pins, and telescoping pin stacks raise pick and bump resistance. Some systems require factory authorization for duplication. The sophisticated appearance often exceeds actual security — a dimple profile alone does not guarantee high security.
Vulnerabilities
Dimple locks remain pin tumblers under the hood: picking, impressioning, decoding, and bumping apply when no countermeasures exist. Pick guns have limited effectiveness because the keyway restricts plug movement. Comb picks and tryout keys still threaten poorly designed models.
Where You Encounter Them
Dimple cylinders appear on apartment entrances across Europe, government facilities, and increasingly on North American commercial retrofits. Locksmiths servicing international hardware should stock dimple blanks and understand manufacturer-specific pinning charts.