Today in History – April 16, 1813- Interchangeable parts for firearms invented Simeon North, who is also generally credited with the invention of the milling machine that made interchangeable parts practical.

Imagine a world where a child is playing with Legos, and in order to connect two of the blocks, the child has to pick up a file and file one (or both) blocks to get them to fit together. Up until the late 1700′s, and into the 1800′s, this is what industrial production was like – custom-fitting of components in a product. To assemble a product (such as a rifle), craftsman would take roughly-shaped parts and then piece them together by hand-filing and grinding.

The advent of “interchangeable parts”, however, allowed the assembly of products to be done much more quickly and by someone without the extensive training of a craftsman. The ability to create these parts came about as a result of steadily improving technology in machine & measurement tools, manufacturing processes, and standards.

These parts in turn led to the world of mass production, where products such as cars, appliances, electronics, etc. can be produced at a cost attainable by a much larger number of people than if each product needed to be hand-crafted. So you can thank the innovators of interchangeable parts for making the widespread availability of all sorts of products – including those little toy blocks which you can use to create your own Lego world.

Building on the concept of standardization and exchangeable parts, Ford introduced the continuous moving assembly line in his Highland Park, Detroit, Michigan, factory. Using a continuous moving chassis line the method was so successful that the Ford Motor Company became the world’s largest car manufacturer in the world. For more information, see the Engineering Pathway’s resources on automotive engineering and manufacturing processes. Additional curricular materials on modern manufacturing practices can be found on the Manufacturing Engineering Education or the Industrial Engineering Education community sites.