Locks

Double-bit lock

Last reviewed on 09. August 2026 1 min read by Tim Herberger, Fachredaktion bei Bremer Tresor

The double-bit lock is a high-security key lock. Due to its complex mechanics, forced entry with a lock pick is impossible. Each component of the lock is precisely adapted to the key, meaning improper opening attempts remain unsuccessful.

The double-bit lock is installed as standard in all our models, but it can easily be exchanged for an electronic combination lock for an additional charge.

Design

How it works

The double-bit lock consists of several tumblers and a locking tongue. To allow the locking tongue to be guided into the recesses of the tumblers, these must be raised to the correct height. A normal key has a key bit that aligns the lock with the help of a spring. In the case of a double-bit lock, however, the lock must be brought exactly into position using both bit sides of the key. By turning the key, the corresponding tumbler is lifted perfectly into position; only then can the locking tongue be moved.

Double-bit key with bits on both sides of the shaft
Both bits engage simultaneously, making lock picks ineffective
Opened double-bit lock, view of the stacked tumblers
Each tumbler must be at its exact height
Locking tongue of a double-bit lock in the recesses of the tumblers
Only then does the locking tongue release the bolt
In case of damage

Replacement in the event of a defect

The double-bit lock is very robust and can still be opened even after massive attempts at destruction or in the event of a fire. If problems should nevertheless occur during opening, parts of the locking system, the key, or the entire lock can be replaced by our team of experts.

Please feel free to contact us directly or use the contact form on the Safe Repair page to receive further information on replacement.

Product range

Safes with a double-bit lock

Bremer Tresor equips all safes as standard with a high-quality double-bit high-security lock. The high mechanical resilience and low wear ensure the high security of the safe. Please feel free to take a look at our safes with a double-bit lock.

Complete double-bit lock of a Bremer Tresor security cabinet
Standard equipment in all models, at no extra cost
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Overview article Safe locks
Tim Herberger
Tim Herberger
Fachredaktion bei Bremer Tresor

Tim Herberger schreibt die Ratgeber von Bremer Tresor. Er bereitet Normen, Vorschriften und Praxiswissen so auf, dass daraus eine klare Kaufentscheidung wird, und gleicht jeden Text mit unseren Fachleuten aus Beratung und Service ab.

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Frequently asked questions

Is the double-bit lock included in the price?
Yes. Bremer Tresor equips all models with a high-security double-bit lock as standard, at no extra charge. Only switching to an electronic combination lock costs extra.
Can a double-bit lock be opened with a lock pick?
No. With a double-bit lock, both bitted sides of the key must raise all tumblers to the exact right height simultaneously. This cannot be replicated with a lock pick.
Can I upgrade to a combination lock later?
Yes, switching to an electronic combination lock is possible for an additional charge and is carried out by our service team. More information can be found at Retrofitting a safe combination lock.
Does the lock still work after a fire?
Generally, yes. The double-bit lock is purely mechanical and very robust
What should I do if I lose my key?
As long as one key is still available, a replacement key can be ordered using the lock number