“These precision tools drill, cut, press, and bore; they are the beating heart of the process, and without them there is nothing for assembly lines to assemble. For example, eighty-seven tools were required to build a single propeller shaft, and in 1940 virtually all such tools came from just two hundred companies, most in New England with fewer than one hundred employees.”
―
Dan Hampton,
Vanishing Act: The Enduring Mystery Behind the Legendary Doolittle Raid over Tokyo