Screw Thread Production to Close Limits - Manufacturing Methods of Threading and Tapping and the Special Tools Developed for Accurate Quantity Production #246116

Like many other basic discoveries of mechanics, the screw thread remained little more than a principle for centuries. Leonardo da Vinci developed it further and from it evolved the principle of the screw propeller, but as this did not receive any practical application until many hundreds of years later, he was, like many other advanced thinkers, away ahead of his time. Some of the early uses of the screw thread were its application to the instruments Of torture employed by the Inquisition, to baling or compressing devices and to the earliest attempts at printing. A descendant of the latter still exists in the form of the Old style letter — copying press.