Two Whitworth surface plates 6" x 4" in box

Made:
1850-1892 in Manchester
maker:
Joseph Whitworth

Two Whitworth surface plates 6" x 4" in box

Flat plane surfaces, to act as references and to form the basis for measurement, are essential to machine tool manufacture and to mechanical engineering. Originally, to make surface plates, two pieces of iron were filed and lapped to fit. However, if one was convex and the other concave, they could still fit together and appear flat. Whitworth, following Maudslay, prepared the plates by matching three, thus ensuring perfectly flat surfaces.

Details

Category:
Industrial Metrology
Object Number:
1913-676
Materials:
cast iron
Measurements:
object (each): 1.378 x 5.9843 x 4.0157 in.; 3.5 x 15.2 x 10.2 cm
type:
surface plate
credit:
Cole, A.S.