Dimple Locks Explained: How They Work, Where You Find Them, and How to Pick Them

Dimple locks turn a pin tumbler on its side and read it from the flat of the key. They carry more pins, tighter tolerances, and a reputation for resisting picking. Here is how the mechanism works, where you will run into one, how secure it really is, and the three ways to pick it.

What is a dimple lock?

A dimple lock is a variant of the pin tumbler mechanism. Instead of a toothed key edge, the key has small dimpled pockets milled into its flat faces, and the cylinder's pins press against those faces from the side or underneath. When the correct key enters the keyway, each pin meets a dimple of the precise depth needed to bring its pin pair to the shear line, and the plug can rotate.

The mechanism is most strongly associated with European front-door cylinders and high-security padlocks. Mul-T-Lock, EVVA, ABUS, ISEO, and DOM are among the best-known dimple-cylinder makers.

How dimple locks work

Mechanically, a dimple lock is still a pin tumbler. Spring-loaded driver pins push key pins down into the plug, blocking it from rotating until every pin pair is lifted, or pulled outward, to align with the shear line. The difference is geometry: pins enter from the side or bottom of the keyway instead of the top, and they bear against the flat of the key rather than its edge.

That single change brings several practical advantages over a standard pin tumbler:

• More pins per cylinder. Dimple locks routinely run 6, 8, 10, or even 12 pin stacks where a residential pin tumbler typically has 5 or 6.
• Tighter tolerances. Mass-market dimple cylinders are machined to tighter dimensions than typical pin tumblers, so feedback is weaker and security pins set less obviously under the pick.
• Multiple pin rows. Some high-security designs use two or three rows of pins simultaneously, so every row must be lifted to the correct depth before the plug rotates.
• Sidebar augmentation. Higher-end dimple cylinders add a sidebar that reads notches on the key's sides, so the picker has to defeat both the shear line and a separate sidebar code.

Where you will find dimple locks

Dimple locks are the default high-security format across much of Europe and turn up wherever extra picking resistance is wanted:

• Front-door cylinders on European homes, particularly across Germany, Italy, the Netherlands, France, and the Nordic countries. Most euro-profile cylinders are available in both pin tumbler and dimple variants.
• Higher-security padlocks from brands such as ABUS, Mul-T-Lock, and EVVA.
• Commercial master-key systems where extra pinning depth simplifies the keying chart.
• High-end safe deposit box cylinders.
• US deadbolts from premium brands, most notably Mul-T-Lock.

In the US, dimple locks remain uncommon on residential doors but show up on imported euro-profile installations, premium deadbolts, and security-rated padlocks.

How secure are dimple locks?

Dimple locks sit toward the higher end of the security spectrum, but the range is wide. Three things determine how secure a particular dimple lock actually is:

• Pin count and pinning depth. A 6-pin standard-depth dimple lock is barely harder than a quality pin tumbler. A 10-pin dimple lock with multiple rows of pins is exponentially more demanding.
• Security pins. Spool, serrated, and T-pins resist picking the same way they do in a pin tumbler. High-security dimples often use security pins in every position.
• Sidebars and active elements. A sidebar adds a second layer that has to be solved alongside the shear line, and active key elements such as movable pins or magnetic interactives defeat most picking attempts outright.

A budget dimple cylinder offers similar real-world security to a mid-range pin tumbler. A well-specified high-security dimple from a recognized maker is one of the most picking-resistant common mechanisms you will meet.

How to pick a dimple lock

Three approaches work on most dimple locks. The right one depends on the cylinder in front of you, the time you have, and whether you need a working key afterwards.

1. Single-pin picking with dimple-specific picks

A dimple keyway is too narrow for a standard hook pick to reach the pins. A dimple pick has a different shape: it enters the keyway flat-on, reaches outward or downward to engage a pin from the side, and lifts it to the shear line. A complete dimple pick set typically pairs 4 to 8 differently-shaped picks with one or two dedicated dimple tension wrenches that grip on the flats of the keyway rather than its corners.

Single-pin picking a dimple lock is slower and more demanding than a pin tumbler. Pin feedback is weaker, multiple rows often have to be solved together, and security pins set less obviously. A clear dimple practice cylinder is the fastest way to build the muscle memory before attacking a real cylinder.

2. Raking with dimple rakes

Dimple rakes have profiles cut to roughly match common dimple spacings. Under light tension, a dimple rake can set easier dimple locks within a few passes. Raking is fast to attempt and rarely opens high-security dimples, but it is the right first move on residential dimple cylinders where you do not need to preserve the lock or cut a key.

3. Bump keys

Dimple bump keys exist for many of the most common dimple cylinders, including Mul-T-Lock and ISEO. The technique is the same as standard bumping: insert a bump key cut for the cylinder's keyway, apply light tension, and strike the key to transfer kinetic energy through the pin stacks. Bumping is faster than picking but unreliable on cylinders with anti-bump pins, sidebars, or active elements.

Dimple vs pin tumbler at a glance

Both mechanisms read the key with pins meeting a shear line. The geometry, pin count, and tolerances put them at very different places on the security curve.

Both rows describe typical examples. A budget dimple is barely harder than a good pin tumbler; a high-security dimple is one of the most picking-resistant common mechanisms.