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

The loose rivets let the hook move by its own thickness on purpose. The figure is taken from National Institute of Standards and Technology, 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.

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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

Tape measure hooks slide to allow inside measurements

The loose rivets let the hook move by its own thickness on purpose The metal hook at the end of a retractable tape is deliberately loose by about a millimetre, the thickness of the hook itself. Pulling the tape against an edge measures from the outside of the hook, while butting it into a corner lets the hook slide in so the reading starts from the inner face. Fixing the hook rigidly would make every inside measurement wrong by that amount. It sits in Mondo's everyday life collection, one of 200 facts that each trace back to the reference below.

Where this comes from

National Institute of Standards and Technology

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Tags: tools, measurement, workshops

Tape measure hooks slide to allow inside measurements: the short answers

Where does this come from, and can I check it?: The loose rivets let the hook move by its own thickness on purpose. The figure is taken from National Institute of Standards and Technology, 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.