How cars are made
In 1913 Ford cut a car's assembly time from 12.5 hours to 1 hour 33 minutes by moving the car past the workers.
- stations
- 8
- things upstream
- 124
- raw sources
- 31
- steps from the ground
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The short version
A car begins as flat steel and aluminum sheet pressed into body panels, which robots weld into a shell. The shell is dipped, painted and baked, then rolls down an assembly line where engine, glass, wiring, seats and wheels are fitted. Each finished car is filled with fluids and tested before it leaves the plant.
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Press the body panels
Giant presses close on flat sheet and bend it into doors, hoods, roofs and fenders in a single stroke. Many carmakers use steel for most panels and aluminum for a few lighter ones.
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Weld the body shell
Robots join hundreds of pressed pieces into one rigid shell, called the body-in-white. Modern shells include a steel safety cage around the passengers.
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Dip and spray the shell
The bare shell is lowered through baths that protect it from rust, then sprayed with colored paint and clear coat. Paint was once the slowest step on Ford's line, because only one type of black would dry fast enough.
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Install the wiring and electronics
A wiring loom is threaded through the body, then screens, sensors and control units are plugged in. A modern car carries many computers.
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Fit glass, seats and trim
Workers glue in the windshield, bolt in seats, lay carpet and clip the dashboard in place. Airbags are installed in the wheel, dash and doors.
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Marry body to powertrain
The painted body, already fitted out inside, is lowered onto the engine, transmission and suspension, which have been built up on a separate line. Bolts at a handful of points hold the two together.
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Mount the wheels
Tires are fitted to wheels, balanced, and bolted on by a machine that tightens all the nuts at once.
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Fill up and road-test
The car receives fuel and fluids, starts for the first time, and is checked on rollers and a test track for leaks, rattles and alignment.
Goes in
Worth repeating
- The world made 56 million cars in 2020, down from 67 million the year before.
- Typical cars weigh between 1 and 3 tonnes, though the small Wuling Hongguang Mini EV weighs about 700 kilograms.
Back to the ground
Follow every input upstream and car starts as these 31 raw sources.
Everything it is made of See it on the map
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Where it comes from
2020, cars manufactured.
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Sources
Cite this page: "How cars are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/car