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

Nearly all threads are right handed, so turning one way drives the screw in. The figure is taken from International Organization for Standardization, 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.

Mondo Knows Facts

Screws tighten clockwise by an old convention

Nearly all threads are right handed, so turning one way drives the screw in A right-hand thread advances when turned clockwise, and that direction became the default for bolts, jars and bottle caps. Left-hand threads appear where rotation would otherwise loosen the joint, such as the left pedal of a bicycle, which tightens as you pedal. Mixing the two is a classic source of stripped threads. It sits in Mondo's everyday life collection, one of 200 facts that each trace back to the reference below.

Where this comes from

International Organization for Standardization

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: threads, engineering, tools

Screws tighten clockwise by an old convention: the short answers

Where does this come from, and can I check it?: Nearly all threads are right handed, so turning one way drives the screw in. The figure is taken from International Organization for Standardization, 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.