I used to work for a company that made stamping dies for aluminum cans, and some of those dies had tolerances close to .0004", because the aluminum is very thin and could crack and tear if the dies were not made precisely. The cans themselves are not that precise, they just need to hold beer without exploding.
I can’t speak to Legos, but cars absolutely do not need this kind of precision, not even in the bearings. And especially not in the sheet metal body panels.
Legos famously have a weirdly high tolerance for injected molded plastic*, it’s part of the branding they use to justify their high price. It does make them snap together more reliably than Mega Blocks or whatever, but Mega Blocks or whatever usually snap together anyway, so I don’t know whether that extra precision counts as necessary.
* People quote all sorts of tolerances for this, but the most credible-looking one I found was 0.04 mm.
I used to work for a company that made stamping dies for aluminum cans, and some of those dies had tolerances close to .0004", because the aluminum is very thin and could crack and tear if the dies were not made precisely. The cans themselves are not that precise, they just need to hold beer without exploding. I can’t speak to Legos, but cars absolutely do not need this kind of precision, not even in the bearings. And especially not in the sheet metal body panels.
Legos famously have a weirdly high tolerance for injected molded plastic*, it’s part of the branding they use to justify their high price. It does make them snap together more reliably than Mega Blocks or whatever, but Mega Blocks or whatever usually snap together anyway, so I don’t know whether that extra precision counts as necessary.
* People quote all sorts of tolerances for this, but the most credible-looking one I found was 0.04 mm.
within 10 micrometers apparently
Legos company profile page 20 specifies that they must have tolerances within 10 micrometers
I assume. It was quoted on Wikipedia, but I can’t be assed to look thru it myself. The pdf is linked if you want to