Mondo Knows Facts
A padlock shackle is held by a notch
Ball bearings or a latch drop into a cut groove to lock the hardened loop The U-shaped shackle has a notch near its short end where locking balls sit, pushed inward by springs and trapped by the plug when the key turns. Turning the key lines up a gap that lets the balls retract, so the shackle springs open. Hardened shackles resist sawing because the steel is too hard for a hacksaw to bite. It sits in Mondo's everyday life collection, one of 200 facts that each trace back to the reference below.
Where this comes from
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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More facts like this
A deadbolt has no spring, unlike a door latchThe latch slides back by spring and bevels to close, but the bolt does notLong door cylinders can be snapped at the middleThe weak point sits where the lock body meets the handle plateCombination locks release when internal notches line upEach dial turns a disc with a gap, and all the gaps must meet at onceCylinder pin-tumbler door locks align split pins along a shear lineKey ridges lift spring-loaded split pins to unlock door cylindersDoor key notches act as mechanical physical passwords for locksGround key blade cut depths lift internal door pins to the exact shear linePress studs click shut as a split ring springsA domed brass ring in the socket spreads, then closes behind the stud
🧭 Everyday Lifefact 131 of 200
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Tags: locks, security, metalwork
A padlock shackle is held by a notch: the short answers
- Where does this come from, and can I check it?
- Ball bearings or a latch drop into a cut groove to lock the hardened loop. 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 2,600 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.