Before the days of British engineer Henry Maudslay, (1771-1831), screws were handmade and depended on the skill of the craftsman. Consequently, no two screws were alike or interchangeable.
In 1797 Maudslay created precision machinery that enabled identical screws to be produced. Without Maudslay's standardization, tasks such as building flatpack furniture would be extremely difficult.
Maudslay was the skilled apprentice of the lockmaker Joseph Bramah, Their working partnership failed when Maudslay and Bramah fell out over pay, causing Maudslay to set up his own shop in another part of London. In a quest for precision, he devised a screw-cutting lathe capable of cutting down reliably to a ten-thousandth of an inch.
To existing lathe designs Maudslay introduced gears and a lead screw that changed the pitch (distance between a complete turn) of the screw. This allowed him to cut a range of thread pitches from the same machine, rapidly and with an accuracy and control previously unseen. Maudslay's identical screws were immediately put to good use in the manufacturing of steam engines. One of his apprentices, Armstrong Whitworth, later standardized screw thread, and today's U.K. imperial unit for thread sizes is the British Standard Whitworth (BSW).
Precision screws led to the start of another Maudslay endeavor, the machine tool, a tool that makes other tools, which was to play a key role during the English Industrial Revolution.
