Tools & manufacturing · 1848

Micrometer caliper

A fine screw turns into measurements of a hundredth of a millimeter.

Jean Laurent Palmer patented a handheld screw micrometer in 1848, and Brown and Sharpe popularized it from 1867. Cheap precision measurement let shops hold tolerances on the factory floor.

See it in the living tree Wikipedia

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

Screw-cutting lathe 1800

Related measurements

The dashed line marks when it first worked.

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