Evidence of the use of interchangeable parts can be traced back over two thousand years to Carthage in the First Punic War. Carthaginian ships had standardized, interchangeable parts that even came with assembly instructions akin to "tab A into slot B" marked on them.3
In the late-18th century, French General Jean-Baptiste Vaquette de Gribeauval promoted standardized weapons in what became known as the Système Gribeauval after it was issued as a royal order in 1765. (At the time the system focused on artillery more than on muskets or handguns.) One of the accomplishments of the system was that solid-cast cannons were bored to precise tolerances, which allowed the walls to be thinner than cannons poured with hollow cores. However, because cores were often off-center, the wall thickness determined the size of the bore. Standardized boring made for shorter cannons without sacrificing accuracy and range because of the tighter fit of the shells; it also allowed standardization of the shells.4
Before the 18th century, devices such as guns were made one at a time by gunsmiths in a unique manner. If one single component of a firearm needed a replacement, the entire firearm either had to be sent to an expert gunsmith for custom repairs, or discarded and replaced by another firearm. During the 18th and early-19th centuries, the idea of replacing these methods with a system of interchangeable manufacture gradually developed.56 The development took decades and involved many people.78
Gribeauval provided patronage to Honoré Blanc, who attempted to implement the Système Gribeauval at the musket level. By around 1778, Honoré Blanc began producing some of the first firearms with interchangeable flintlock mechanisms, although they were carefully made by craftsmen. Blanc demonstrated in front of a committee of scientists that his muskets could be fitted with flintlock mechanisms picked at random from a pile of parts.9
In 1785 muskets with interchangeable locks caught the attention of the United States' Ambassador to France, Thomas Jefferson, through the efforts of Honoré Blanc. Jefferson tried unsuccessfully to persuade Blanc to move to America, then wrote to the American Secretary of War with the idea, and when he returned to the USA he worked to fund its development. President George Washington approved of the concept, and in 1798 Eli Whitney signed a contract to mass-produce 12,000 muskets built under the new system.10[need quotation to verify]11
Between 4th July 1793 and 25th November 1795, the London gunsmith Henry Nock delivered 12,010 'screwless' or 'Duke's' locks to the British Board of Ordnance.12 These locks were intended to be interchangeable, being manufactured in large volumes in a steam-powered factory using gauges and lathes. Subsequent experiments have suggested that the lock's components were interchangeable at a higher rate than those of the later British New Land Pattern musket and the American M1816 musket.13
Louis de Tousard, who fled the French Revolution, joined the U.S. Corp of Artillerists in 1795 and wrote an influential artillerist's manual that stressed the importance of standardization.14
Numerous inventors began to try to implement the principle Blanc had described. The development of the machine tools and manufacturing practices required would be a great expense to the U.S. Ordnance Department, and for some years while trying to achieve interchangeability, the firearms produced cost more to manufacture. By 1853, there was evidence that interchangeable parts, then perfected by the Federal Armories, led to savings. The Ordnance Department freely shared the techniques used with outside suppliers.15
In the US, Eli Whitney saw the potential benefit of developing "interchangeable parts" for the firearms of the United States military. In July 1801 he built ten guns, all containing the same exact parts and mechanisms, then disassembled them before the United States Congress. He placed the parts in a mixed pile and, with help, reassembled all of the firearms in front of Congress, much as Blanc had done some years before.16
The Congress was captivated and ordered a standard for all United States equipment. The use of interchangeable parts removed the problems of earlier eras concerning the difficulty or impossibility of producing new parts for old equipment. If one firearm part failed, another could be ordered, and the firearm would not need to be discarded. The catch was that Whitney's guns were costly and handmade by skilled workmen.
Charles Fitch credited Whitney with successfully executing a firearms contract with interchangeable parts using the American System,17 but historians Merritt Roe Smith and Robert B. Gordon have since determined that Whitney never actually achieved interchangeable parts manufacturing. His family's arms company, however, did so after his death.
Mass production using interchangeable parts was first achieved in 1803 by Marc Isambard Brunel in cooperation with Henry Maudslay and Simon Goodrich, under the management of (and with contributions by) Brigadier-General Sir Samuel Bentham,18 the Inspector General of Naval Works at Portsmouth Block Mills, Portsmouth Dockyard, Hampshire, England. At the time, the Napoleonic War was at its height, and the Royal Navy was in a state of expansion that required 100,000 pulley blocks to be manufactured a year. Bentham had already achieved remarkable efficiency at the docks by introducing power-driven machinery and reorganising the dockyard system.
Marc Brunel, a pioneering engineer, and Maudslay, a founding father of machine tool technology who had developed the first industrially practical screw-cutting lathe in 1800 which standardized screw thread sizes for the first time,19 collaborated on plans to manufacture block-making machinery; the proposal was submitted to the Admiralty who agreed to commission his services. By 1805, the dockyard had been fully updated with the revolutionary, purpose-built machinery at a time when products were still built individually with different components. A total of 45 machines were required to perform 22 processes on the blocks, which could be made in three different sizes. The machines were almost entirely made of metal, thus improving their accuracy and durability. The machines would make markings and indentations on the blocks to ensure alignment throughout the process. One of the many advantages of this new method was the increase in labour productivity due to the less labour-intensive requirements of managing the machinery. Richard Beamish, assistant to Brunel's son and engineer, Isambard Kingdom Brunel, wrote:
So that ten men, by the aid of this machinery, can accomplish with uniformity, celerity and ease, what formerly required the uncertain labour of one hundred and ten.
By 1808, annual production had reached 130,000 blocks and some of the equipment was still in operation as late as the mid-twentieth century.202122232425
Eli Terry was using interchangeable parts using a milling machine as early as 1800. Ward Francillon, a horologist, concluded in a study that Terry had already accomplished interchangeable parts as early as 1800. The study examined several of Terry's clocks produced between 1800–1807. The parts were labelled and interchanged as needed. The study concluded that all clock pieces were interchangeable. The very first mass production using interchangeable parts in America was Eli Terry's 1806 Porter Contract, which called for the production of 4000 clocks in three years.26 During this contract, Terry crafted four-thousand wooden gear tall case movements, at a time when the annual average was about a dozen.27 Unlike Eli Whitney, Terry manufactured his products without government funding. Terry saw the potential of clocks becoming a household object. With the use of a milling machine, Terry was able to mass-produce clock wheels and plates a few dozen at the same time. Jigs and templates were used to make uniform pinions, so that all parts could be assembled using an assembly line.28
The crucial step toward interchangeability in metal parts was taken by Simeon North, working only a few miles from Eli Terry. North created one of the world's first true milling machines to do metal shaping that had been done by hand with a file. Diana Muir believes that North's milling machine was online around 1816.29 Muir, Merritt Roe Smith, and Robert B. Gordon all agree that before 1832 both Simeon North and John Hall were able to mass-produce complex machines with moving parts (guns) using a system that entailed the use of rough-forged parts, with a milling machine that milled the parts to near-correct size, and that were then "filed to gage by hand with the aid of filing jigs."30
Historians differ over the question of whether Hall or North made the crucial improvement. Merrit Roe Smith believes that it was done by Hall.3132 Muir demonstrates the close personal ties and professional alliances between Simeon North and neighbouring mechanics mass-producing wooden clocks to argue that the process for manufacturing guns with interchangeable parts was most probably devised by North in emulation of the successful methods used in mass-producing clocks.33 It may not be possible to resolve the question with absolute certainty unless documents now unknown should surface in the future.
Skilled engineers and machinists, many with armoury experience, spread interchangeable manufacturing techniques to other American industries, including clockmakers and sewing machine manufacturers Wilcox and Gibbs and Wheeler and Wilson, who used interchangeable parts before 1860.3435 Late to adopt the interchangeable system were Singer Corporation sewing machine (1860s-70s), reaper manufacturer McCormick Harvesting Machine Company (1870s–1880s)36 and several large steam engine manufacturers such as Corliss (mid-1880s)37 as well as locomotive makers. Typewriters followed some years later. Then large scale production of bicycles in the 1880s began to use the interchangeable system.38
During these decades, true interchangeability grew from a scarce and difficult achievement into an everyday capability throughout the manufacturing industries.39 In the 1950s and 1960s, historians of technology broadened the world's understanding of the history of the development. Few people outside that academic discipline knew much about the topic until as recently as the 1980s and 1990s, when the academic knowledge began finding wider audiences. As recently as the 1960s, when Alfred P. Sloan published his famous memoir and management treatise, My Years with General Motors, even the long-time president and chair of the largest manufacturing enterprise that had ever existed knew very little about the history of the development, other than to say that:
[Henry M. Leland was], I believe, one of those mainly responsible for bringing the technique of interchangeable parts into automobile manufacturing. […] It has been called to my attention that Eli Whitney, long before, had started the development of interchangeable parts in connection with the manufacture of guns, a fact which suggests a line of descent from Whitney to Leland to the automobile industry.40
One of the better-known books on the subject, which was first published in 1984 and has enjoyed a readership beyond academia, has been David A. Hounshell's From the American System to Mass Production, 1800–1932: The Development of Manufacturing Technology in the United States.41
Hounshell 1984. - Hounshell, David A. (1984), From the American System to Mass Production, 1800–1932: The Development of Manufacturing Technology in the United States, Baltimore, Maryland: Johns Hopkins University Press, ISBN 978-0-8018-2975-8, LCCN 83016269, OCLC 1104810110 https://lccn.loc.gov/83016269 ↩
Ford, Henry; Crowther, Samuel (1930), Edison as I Know Him (PDF), New York: Cosmopolitan Book Company, p. 30, archived from the original on 2012-10-11, retrieved 2011-09-29 /wiki/Henry_Ford ↩
Rome, Carthage, and the Punic WarsMeanwhile Carthage was mass producing warships. And that's not an exaggeration either about numbers or about shipbuilding methods; Carthaginian warships were built up of standard interchangeable parts. We know this not only from contemporary accounts, but also from recovered Carthaginian ships like the half of a Carthaginian ship shown in (c), above, that was recovered off the coast of Marsala at the western tip of Sicily; it was brand new when it was sunk by the Romans, and it still retains marks giving assembly instructions ("tab a into slot b", etc.) Other recovered ships had identical parts. http://www.mmdtkw.org/ALRIAncRomUnit4Slides.html ↩
Fitch 1882, p. 4. - Fitch, Charles H. (1882), Extra Census Bulletin. Report on the manufacture of fire-arms and ammunition, Washington, DC, USA: United States Government Printing Office. https://books.google.com/books?id=gtZy4zvRRi0C&pg=PP10 ↩
Hounshell 1984, pp. 25–46. - Hounshell, David A. (1984), From the American System to Mass Production, 1800–1932: The Development of Manufacturing Technology in the United States, Baltimore, Maryland: Johns Hopkins University Press, ISBN 978-0-8018-2975-8, LCCN 83016269, OCLC 1104810110 https://lccn.loc.gov/83016269 ↩
James Burke, Connections (Little, Brown and Co.), 1978/1995 ISBN 0-316-11672-6, p. 150 /wiki/James_Burke_(science_historian) ↩
Boorstin, Daniel J. (7 July 2010) [1965]. "From Skill to Know-how: 'A Circulating Current'". The Americans: The National Experience. Americans Series (volume 2). New York: Knopf Doubleday Publishing Group. pp. 31, 32. ISBN 9780307756473. Retrieved 25 February 2024. [...] on May 1 [1798], Eli Whitney of Connecticut wrote the Secretary of the Treasury offering his machinery, water power, and workmen [...] for the manufacture of muskets. Whitney signed a contract for ten thousand muskets, a fantastic number in those days, to be delivered within twenty-eight months. 9780307756473 ↩
Williams, David; Hood, Jamie; Spencer, Dawn; Williams, Alan; Harding, David (2024-09-13). "'The Duke's Lock': a study of the interchangeability of Henry Nock's Board of Ordnance 'Screwless' Lock. Part 1: materials, machines and measurements". Arms & Armour. 21 (2): 33, 19–20. doi:10.1080/17416124.2024.2387930. ISSN 1741-6124. https://doi.org/10.1080%2F17416124.2024.2387930 ↩
Van Dusen 2003. - Van Dusen, Albert E. (2003). "Eli Whitney". Laptop Encyclopedia of Connecticut History. CTHeritage.org. Retrieved 2009-02-18. http://www.ctheritage.org/encyclopedia/ct1763_1818/whitney.htm ↩
Cooper 1984. - Cooper, C. C. (1984), "The Portsmouth system of manufacture", Technology and Culture, 25 (2): 182–225, doi:10.2307/3104712, JSTOR 3104712, S2CID 111936139. https://doi.org/10.2307%2F3104712 ↩
Quentin R. Skrabec, Jr. (2005). "The Metallurgic Age: The Victorian Flowering of Invention and Industrial Science". p. 169. McFarland ↩
"Making the Modern World – Rational manufacture". Retrieved 20 February 2017. http://www.makingthemodernworld.org.uk/stories/enlightenment_and_measurement/05.ST.02/?scene=3&tv=true ↩
"PORTSMOUTH ROYAL DOCKYARD HISTORY". Archived from the original on 26 February 2020. Retrieved 20 February 2017. https://web.archive.org/web/20200226122038/https://portsmouthdockyard.org.uk/Page%206.htm ↩
"Blockmaking - A new departure in manufacturing: Portsmouth blockmaking machinery". Archived from the original on 2001-05-09. Retrieved 2006-09-24. https://web.archive.org/web/20010509194758/http://www.sciencemuseum.org.uk/collections/exhiblets/block/start.asp ↩
Gilbert 1965. - Gilbert, K. R. (1965), The Portsmouth block-making machinery, London, UK: Her Majesty’s Stationery Office. ↩
Cooper 1982. - Cooper, C. C. (1982), "The production line at Portsmouth block mill", Industrial Archaeology Review, VI: 28–44. ↩
Eli Terry and the Connecticut Shelf Clock; Tect ↩
Eli Terry and the Connecticut Shelf Clock; Text ↩
Muir 2000. - Muir, Diana (2000), Reflections in Bullough's Pond: Economy and Ecosystem in New England, University Press of New England, ISBN 978-0-87451-909-9. https://archive.org/details/reflectionsinbul00dian ↩
Gordon 1989. - Gordon, Robert B. (1989), "Simeon North, John Hall, and mechanized manufacturing", Technology and Culture, 30 (1): 179–188, doi:10.2307/3105469, JSTOR 3105469, S2CID 111632820. https://doi.org/10.2307%2F3105469 ↩
Smith 1973. - Smith, Merritt Roe (October 1973), "John Hall, Simeon North and the Milling Machine", Technology and Culture, 14 (4): 573–591, doi:10.2307/3102444, JSTOR 3102444, S2CID 111427243. https://doi.org/10.2307%2F3102444 ↩
Smith 1977. - Smith, Merritt Roe (1977), Harper's Ferry Armory and the New Technology, Cornell University Press ↩
Thomson, Ross (1989). The Path to Mechanized Shoe Production in the United States. University of North Carolina Press. ISBN 978-0807818671. 978-0807818671 ↩
Hunter, Louis C. (1985). A History of Industrial Power in the United States, 1730–1930, Vol. 2: Steam Power. Charlottesville: University Press of Virginia. ↩
Sloan 1964, pp. 20–21. - Sloan, Alfred P. (1964), McDonald, John (ed.), My Years with General Motors, Garden City, NY, US: Doubleday, LCCN 64011306, OCLC 802024. https://books.google.com/books?id=qHJEAAAAIAAJ ↩