Industrial screw micrometer
Micrómetro industrial de tornillo
- Date
- 1848 · confidence high
- Place
- Paris, France
- Credited to
- Jean-Laurent Palmer
- Field
- Knowledge & symbols
What it is
A pocket calliper with a micrometer screw that measured thicknesses to a hundredth of a millimetre. It put precision measurement within reach of any workshop hand.
In France it is still called a 'palmer'.
What it led to
- Quality control at the workbench
- Adoption by Brown & Sharpe (1867) and its spread across the United States
- Tolerances specified on engineering drawings
Built on
- Screw-cutting lathe with slide rest1797-1800
- Maudslay's 'Lord Chancellor' bench micrometerc. 1805
- Workshop vernier caliper (Brown & Sharpe)1851
- Gascoigne's micrometer (1638)
- Maudslay's measuring machine ('Lord Chancellor')
- Whitworth's measuring machine (1834)
Made possible
- Coordinate measuring machinec. 1959
- Mass production with tolerances
- Go/no-go gauges