Meanwhile, on the wood-screw side, hardware manufacturers had developed for their own in-house use the first fully automatic [mechanically automated] special-purpose machine tools for the making of screws.
The 1760–1840 development arc was a tremendous technological advance, but later advancements would make screws even cheaper and more prevalent yet again. These began in the 1840s with the adaptation of the engine lathe with a turret-head toolholder to create the turret lathe.
"This development greatly reduced the time, effort, and skill needed from the machine operator to produce each machine screw. This development greatly reduced the time, effort, and skill needed from the machine operator to produce each machine screw. Single-pointing was forgone in favor of die head cutting for such medium- and high-volume repetitive production.
Then, in the 1870s, the turret lathe's part-cutting cycle (sequence of movements) was automated by being put under cam control, in a way very similar to how music boxes and player pianos can play a tune automatically. According to Rolt (1965), the first person to develop such a machine was Christopher Miner Spencer, a New England inventor. Charles Vander Woerd may have contemporarily independently invented a machine similar to Spencer's.
However, the wood-screw-making machines of the 1840s and 1850s [special-purpose factory production machine tools as opposed to small-machine-shop machine tools], such as those developed by Cullen Whipple of the New England Screw Company and Thomas J. Sloan of the American Screw Company, had anticipated the machines of Spencer and Vander Woerd in various ways, albeit approaching the problem of automated screw production from a different commercial angle.