Henry Maudslays original screw-cutting lathe, c 1800.

UNITED KINGDOM - JULY 30: This lathe is said to be the first workshop machine on which English engineer, Henry Maudslay (1771-1831) combined a lead-screw and change wheels for reproducing screw threads. The bed consists of two triangular bars which carry the headstock, tailstock and slide-rest. The lead-screw is situated between the bars and was geared to the lathe spindle by change wheels (now missing). Before Maudslay�s invention, screws were crudely made by hand. Maudslay went on to produce tools for the production of both ordinary and specialist screws for all types of machines. (Photo by SSPL/Getty Images)