Where does this come from, and can I check it?

Ground key blade cut depths lift internal door pins to the exact shear line. The figure is taken from Encyclopaedia Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Yes. It sits on the Everyday Life shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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Mondo Knows Facts

Door key notches act as mechanical physical passwords for locks

Ground key blade cut depths lift internal door pins to the exact shear line

Physical brass door keys feature a series of ground notches called bittings along the blade edge. Each notch depth corresponds to a numerical pin length inside the lock cylinder. The combination of cut depths represents a mechanical password that lifts internal pins to the cylinder shear line.

Where this comes from

Encyclopaedia Britannica

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Tags: keys, locks, security

Door key notches act as mechanical physical passwords for locks: the short answers

Where does this come from, and can I check it?: Ground key blade cut depths lift internal door pins to the exact shear line. The figure is taken from Encyclopaedia Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a everyday life fact?: Yes. It sits on the Everyday Life shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.