Lego expands its Mexico injection facility with $400 million

Lego has announced an investment of more than $400 million to increase the capacity of its manufacturing complex in Monterrey, Mexico, by 35%. A new packaging building and a fully automated high-bay warehouse will add 62,000 m² to the existing 148,080 m² site. Construction will begin in early 2027 and is planned to finish in 2029; once complete, total employment at the plant will rise to 8,600 (roughly 1,300 new jobs).

Molding to a precision of 0.005 mm

The most striking technical detail for molders in this news is this: the Monterrey plant runs the entire process for injection-molded Lego elements, from molding through painting to boxing. According to the company, every single brick is molded to a precision of 0.005 mm so that pieces fit together exactly and produce the interlocking grip known as "clutch power" — a tolerance window roughly one-tenth the thickness of a human hair.

Micron-level precision at high volume

Hitting micron-level tolerances at this scale (billions of parts a year) is possible not just through precise mold work, but through stable pressure/temperature control throughout the cycle and strict mold maintenance. In such tight-tolerance, high-volume jobs, correctly calculating clamping force and choosing a clamping force that won't produce flash is critical; a tolerance that leaves little margin also leaves very little tolerance for wear on the machine and mold.

What does this mean for a molder?

Although this news looks like an investment announcement, it actually offers a rare public glimpse into one of the industry's highest-volume, tightest-tolerance injection applications. Even in a small workshop, the question "how many microns of tolerance can we hit" is as much about process stability as it is about mold quality.