For an old-school toy, the manufacturing process of LEGO bricks is extremely sophisticated. To achieve the correct fit between the studs and the holes of two bricks – so that they can be clicked together and pulled apart with just the right amount of effort – a maximum tolerance of 0.001 mm is allowed during production. Even with this high standard to reach, only 0.0018% of all bricks are defective. And the few that are defective, of course, are recycled back into ones that aren’t.
LEGO photograph by fdecomite