The use of machine tools began with the onset of the First Industrial Revolution. The increase in mechanization required more metal parts, which were usually made of cast iron or wrought iron—and hand working lacked precision and was a slow and expensive process. One of the first machine tools was John Wilkinson's boring machine, that bored a precise hole in James Watt's first steam engine in 1774. Advances in the accuracy of machine tools can be traced to Henry Maudslay and refined by Joseph Whitworth. Standardization of screw threads began with Henry Maudslay around 1800, when the modern screw-cutting lathe made interchangeable V-thread machine screws a practical commodity.