• harsh3466@lemmy.ml
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    6 hours ago

    Interestingly enough, this concept was used in pattern making for casting machine parts back before modern machining and parts manufacturing.

    They were colloquially called shrunk rulers, and looked like a standard ruler, but was actually longer to account for the shrinkage of the material being cast.

    For example, say you’re casting a part from iron, which shrinks 1% as it cools, which amounts to 1/8 inch per foot.

    An iron shrink rule would look standard, but actually measure a foot as 1 foot 1/8 inches to account for the shrinkage (this is an example and not meant to be actually accurate).

    Source: am historian that interviewed pattern makers that used shrink rulers in their work.